Honestly, I think this channel does a lot to dignify a lot of jobs folks looked down on. When you start to understand how fascinating appliances are, it’s easy to respect the folks who work on them ;). HVAC is pretty nifty stuff, imo.
This is the magic of the "edutainment" side of UA-cam. So many channels I watch have comments on random videos that say "thanks for getting me interested in X, it's now my job/field of study."
I love how this guy can look around his house, point to literally any random thing like a light switch, toaster or hot water heater and give the most in depth and comprehensive explanation about it.
I just now learned about sacrificial anode rods! I wish I had known about them when I bought my house. Everyone always told me you just let the tank rust and replace it when it starts leaking (~10 years). First you had me ditch my dishwasher pods, now this! When I started watching your channel, I had no idea you would be saving me money! Great stuff!
I only recently found out about them. I only really saw them being used on seafaring ships, since the dangers of even galvanic corrosion are far more impactful when you're trundling across more conductive saltwater. Of course... considering that softeners _literally use salt_ as a way to filter out material junk that gets into tap water... I probably should've put two-and-two together by now.
Need to watch those old episodes of "This Old House" they talked about them just about every time there was anything related to a water heater mentioned
Most plumbers will tell you to leave them alone because after years of being in the tank, they can become stuck and you end up damaging the threads trying to unscrew it. Plus they get to sell you a new hot water heater.
I know this is not a DIY or repair channel, but this video actually pointed me in the right direction to diagnose the cause of my short hot water supply. I have a 55 gallon water heater that would run cold just handwashing dishes or during anything but a quick shower. Additionally, I was getting bad smells from my tank. After watching this video, I realized that it was entirely possible I was only running on the top heating element. Sure enough, I had 240v going to the bottom element with no current draw. Resistance measured in the kiloohms. Thanks for inadvertently saving me a small fortune in needlessly replacing a water heater. $30 and I'm able to wash dishes while doing laundry, then go take ahower!
@@aduantas sulfur reducing bacterial build up in the sediment that wasn't getting killed due to the bottom half of the tank never heating up. I took the time to remove as much sediment as I could while I had the lower element out. Apparently, flushing with the bottom valve doesn't do much.
I built water heaters like this once. This doesn't matter, but the foam is injected with the lid off at just the right amount to expand by the time the lid is assembled on the line. The extra holes in the lid is just a multi-use design for many different tanks, such as tanks with multiple fittings for dual zone or aux floor heating.
The extra holes can also be used for additional anode rods. Most HW heater models are priced by warranty years (6, 9 or 12 years). The warranty correlates with number of rods. Save some $$$ by buying the cheapest unit (6-year) and install two more anode rods yourself (get magnesium). That should give 12-years protection. Replace the rods every 12-years and you 'll never need a new WH. I did this in 2013 and am due for a change out next year.
Chiming in from France: it's completely common and very widespread here to have heaters only turn on during hours of lower cost power. There's a system that allows the power company, via the power meter, to send a signal to the heater to turn it on or off (and different neighborhoods are turned on at different hours). I guess a reason for all this is that France uses a lot of electrical water heaters, thus it's important to manage their load on the grid.
Same here in germany. Though nowadays you'd use your excess solar power to heat the water tank rather than letting the energy feed into the grid instead of getting a dual-tariff energy plan.
Also in France much of the electricity is nuclear, and there is a limit to the amount by which one can throttle down the power of a nuclear reactor; if consumption would go down too far at night, they would need to entirely shut down some reactors and start them up again later, which is very costly.
Dutch and came here to say the same thing: the only electric water heaters I've ever used had built-in functionality to only run during low power rates. At least one of them even had a timed override to let/make it run with high rates 'just this once' if you needed extra hot water for some reason. Once the timer ran out it would just reset to using low rates power only.
Late to the comments, I live in Japan with a water heater designed for rate metering and families. It heats the water to 90c during the night and saves it in a giant outdoor tank, distributing the almost boiling water to a reasonable pre-set temp by mixing It with cold water, essentially storing “hot water concentrate” to use to make way more “hot water” than it could ever store - providing enough hot water for 4-5 people for the whole day with some buffer. A control panel lets you ask to make more on demand (guests), and also, separately, manages filling and reheating bathtub water for bathing. It uses 9-12 KW of very cheap power at night, not drawing power the rest of the day in normal operation. This system was installed in ~2006.
こんばんは (here in TX anyway). 90°C, that's pretty toasty. Talk about super-instant noodles with that water. 9-12 kW is a bit of usage, but hopefully it's not having to run terribly often. Good you have gotten almost 20 years of usage out of it; sounds like a pretty solid system.
As a mech engineer working in industry, I have to say I love your channel. Sure we have understanding of the mathematical concepts in these vids but things like this I had no idea about. Please don't ever stop making videos like this.
They are called Twin Element hot water tanks here in Australia, and are marketed as such. They don't seem to be that common here. The majority are single bottom element types, probably because of our generally warmer climate. Yes, tank stratification is an interesting topic, it made calcs in my recent whiteboard video on heat pump hot water tanks pretty much just a guess without knowing the actual water flow rates and in/out temps.
I've never seen twin element hot water heater where I live (Norway) and our tap water is around 4-5c most of the year. This is yet another weird american thing I bet.
They are common in the UK since the switch from vented cylinders (which are supplied from a header tank in the attic) to unvented cylinders that are connected to the incoming water main supply. The heating elements are often used as boost heaters as they tanks usually have an indirect coil carrying hot water from the central heating system which heats the water.
They are known as immersion heaters in the UK, often abbreviated to 'the immersion' and they are almost always on a timer and we don't have huge outbreaks of legionnaires disease.
Two elements is pretty standard in Canada. Here's an idea. Set the top thermostat to 45C, set the bottom thermostat to 55C, then put that contactor in series with the bottom element. So now the bottom element heats the entire tank to 55C at the cheap rates and is then disabled. The top heater doesn't do anything at all unless you run completely out of hot water, but is still able to kick in if necessary.
18:05 I discovered this by accident, we went on holidays for two weeks on summer and we turned off our water heater, when we came back, at the following morning both my parents had a shower and later at night I did, and I've noticed that after five minutes the water was getting unusually cold, turns out we forgot to turn on the heater, and it still had hot water for almost 3 showers, only being FOURTY (40) litters (10,5 gallons) I was amazed
I just changed my anode a few weeks ago. A plumber let me in on the secret after a water heater needed to be replaced in my house years ago. Couple of things to note: If your water heater is in a space with a fairly low ceiling you may not be able to get the original factory installed anode out without cutting it in half while you remove it. They are quite long. Easy job for an angle grinder, might be difficult to do with a hacksaw! use some vice grips to hold the bottom half and stop it from falling back into the tank. You can buy flexible ones to replace them for these situations. Every 5 years is a good rule of thumb, but this does depend on your water quality, things like chlorine and mineral content will affect the rate of corrosion. When I swap the anode I write on the side of the tank with a sharpie the date I did it so I can refer back to it. At 5 years mine still had a good bit of life left in it but I swapped it anyway because I was already that far into the job. You might need a hefty 1-1/16" socket to remove the anode and sadly the factory will usually tighten them down super tight, the first time I removed mine I needed to use an impact gun to shift it, you might think a breaker bar would work but water heaters are usually not fixed down well enough, you could end up damaging something. If you plan to do this you need to turn the water off and drain the tank. You might think you only need to drain a tiny bit out but remember your output is connected to the house, if you're in there with the anode out and someone opens a hot tap upstairs gravity will allow the water in the pipes to drop down and fill the tank. Make sure you drain plenty of water out. You might as well drain enough to remove any sediment which is good practice anyway - some people would say to do that annually. Even if you have to buy the right socket - anodes cost around $30. Compare that to the cost of new water heaters... with installation, removal of the old one and any damage they do when they leak? could be a 4 digit number pretty easily. Use this math to convince yourself or others that you're actually saving money when you go buy an angle grinder and an impact gun. fun tip. The drain valve on most modern water heaters has a thread that allows typical garden hoses to connect to it, this can help simplify the draining process so you dont need a lot of buckets.
I would add to this that for those of us with water softeners the anode can be consumed in as little as a year due to increased conductivity of the sodium ions. Myself, I installed a permanent electronic anode which can be transferred to a new water if needed.
@@sorin.n Maybe he means the kind of anodes that are popular in Europe: a titanium one (that is not consumed) which is maintained under a small voltage by an electronic controller. It uses the magnesium in the water to protect the inside. (or it is sometimes coupled with a pre-installed magnesium anode, but the magnesium does not escape because of the constant small current in the tank. It is generally equipped with a small battery to maintain the magnesium/calcium in place, because in Europe water heaters are mostly powered only at night: a signal sent every evening and morning over the wire from the electricity company put/cut the power when the tariff changes.
good points, another is to swap out the cheapo plasticko drain valve to a ball valve which moves a lot more water, like just 10 seconds wide open cleans out any bottom sediment, adding a quick attachment snap on ( garden hose ) makes this maintenance job easy.
I don't know if anyone's ever said this before, but THANK YOU for making the captions line up exactly with what's being said (in addition to sneaking in a haha funny or two)! I hate having to pause to read frame-long walls of text that aren't even being spoken, and since I use captions for the sake of auditory processing, I can hear all the minor mismatches and just end up irritated. Thank you for doing our eyes and ears a service!
Yeah, you'd think UA-cam auto captions could line up perfectly since they have the time stamps of the audio, but I guess it's not a high enough priority
I inspect failed water heaters for a living. You happen to have one of the most reliable models I've ever seen. I've seen some of those GE (which were made by rheem) go 20 years.
Are the ones you encounter mostly electric? Here in Germany we generally have oil and gas heated tanks and they mostly fail because of rusting and then having a hole in the bottom but the ones I know of are at least older than 15years, which is the mean lifetime given by the manufacturer.
My 40 gal water heater was 24 years old when it finally absolutely needed replacing in 2020, but I bet anyone who knows water heaters would've known it needed replacing long before I found out. Looking back at the symptoms, I think I let it go about 10 years too long.
Plumber here. The oldest functioning electric water heater I've seen was 37 years old. It had never had any maintenance and still had the original thermostats, elements, and anode rod (which was completely gone for most of that time). I didn't recommend replacing it. Why not? Well the reason it had never leaked is because it happened to have a perfect glass lining from the factory. The inner steel tank is sprayed with molten glass, and usually that coating isn't perfect, so the anode rod helps protect any exposed steel from corrosion. But once in a blue moon, a tank leaves the factory with a perfect glass coating. This was one of those, and as such it will never, ever leak. So I left it in place!
As a plumber, I have to say this was a great explanation of operation and details of design. If you get the chance, pull an old thermostat and high limit off an electric tank so that you can see how they work. They're very simple but interesting as well.
I have recently been wondering exactly how it refills and heats without diluting the already-heated water. Neat that it's merely the strength of the thermal stratification. Thanks for explaining!
It also explains in part why toward the end of their lives, hot water heaters produce less hot water. After the sacrificial anode erodes away, the galvanic corrosion attacks the dip tube that carries the cold water to the bottom of the tank so in stead it cools the water at the top of the tank.
@@bcbock Dip tubes are plastic where I am. And if you've ever been scuba diving, it's really amazing to encounter a thermocline, where the water at your palm is 65F and the water at your fingertips is 40F.
@@bcbock That's mostly explained by the bottom element being used more often, and tending to fail long before the top element fails, so instead of it heating the bottom of the tank, the top element is the only one that turns on, and heats just the top of the tank. often you can drain the tank and replace that bottom element and solve the problem of the tank having less hot water in it.
Stupid thing is I KNOW the layers not mixing happens even in the oceans, yet it would've never occurred to me this also happens in water tanks with a higher temperature difference, or that this could be used to simply push hot water up with a cold water column....
The engineering of water heaters is fascinating- the MythBusters did some experiments with them and found that while they can fail, it takes some real effort to do so.
Yes, but when they do fail, it's spectacular - probably why the manufacturers make it so hard to actually make one fail. Stored energy is quite the thing.
@ccoder4953 absolutely! Even in nature, water is an incredible force. Put it under heat and pressure, and you got something amazing. Or terrifying. It really depends.
this makes a lot of sense, anything that can store 7kwh of energy in thermal form is 99% of the way to being a bomb, so of course they'd engineer it for safety
This is hands down one of the best channels on UA-cam. You restore some of the wonder I felt as a child who liked to take things apart and figure out how they worked. I really appreciate the level of research and thought you put into each video.
I just installed a heat-pump water heater this past weekend and the change in energy usage is crazy (like 10-12kWh of power a day down to 2.5), and I have it sucking in and blowing out air to the same place. Not great for all areas (I'm in FL, so it helps cool my house down now, too), but wow I'm impressed. Just crazy that i did it and saw your newest video (which apparently I'm 3 weeks late to, lol)!
I am in upstate NY and have a heat pump hot water heater and it is great. It’s in our unfinished basement and we use it all year. It dehumidifies the basement and it cost much less than an electric hot water heater to operate. Free basement dehumidifier without the putting heat into the room makes sense even during our cold winter months.
Converting electricity into heat directly is 100% efficient. But if you move heat from one place to another, you can get more than 4x the heat from the same amount of energy (which is where 300%-400%-500% efficiency figures come from).
@@1Eagler After Ian hit last year, seeing all my neighbors with solar heaters on their roofs being yanked off, I'm keeping everything off of it if possible.
Beyond the amount of effort you put into your videos for 11 out of 12 months, I want to thank you for including captions in your videos. It really helps me out.
One thing that could be changed here is sometimes his notes embedded into the video end up behind the captions, making the former impossible to read thus they need to be placed higher on the screen.
Idea: You might also want to properly insulate the hot water pipes coming from the boiler to the ceiling of this room. Reason being: Since I added insulation, I noticed that the water gets hot at the tap/shower sooner than before.
@@igotes you should get an ever so slightly more efficient heated blanket. Living in an very old house converted to all electric in the Midwest and it's a life saver and money saver
As a woman who's a lifelong renter and has a father who perpetually sees me as being 16, your videos are invaluable to me, Mr. Connections. The look on my dad's face when I actually know things about household appliances is just golden!
Smart home idea: add some sort of temperature detector (or a few of them) to your water heater, and next to each shower add a display that indicates how much hot water is available, and potentially also estimate time until the water is hot and whether hot water is already in use somewhere else in the house.
@@schok51 me too. but i was discussing retail price, not wholesale price. if a large commercial endeavour can fuck the little guy over, they simply go in with no lube.
For the labor, cost, and complexity of the displays, temp sensors, flow sensors, wiring, and computer needed to make that work, it would make so much more sense to just get a large enough (or tankless) water heater and eliminate that concern.
The surpassingly sharp boundary between hot and cold water also happens in lakes. When the ice goes out in the spring the water mixes because it’s all roughly the same temperature, but once the top layer warms up the turnover stops. That’s why when you’re out swimming in a lake you’ll sometimes dive deep enough and notice a very abrupt change in temperature.
Even more incredible, it happens in the ocean, even though there are tides and currents. In fact, it is what allows currents - the oceans are basically one massive, looping conveyor belt (with smaller subsidiary loops as well) of water, driven by gravity. The only time they gain or lose much heat is when in contact with the surface, and since polar air is cold, and cold water is dense, it sinks. As it travels around the world, it stays cold until it comes up to the surface. (This is why the deep ocean everywhere is just above freezing.) That journey around the world? About 5000 years, if I recall correctly. The lack of mixing also has a crazy side effect - you can map out where there is more deuterium and tritium, from aerial nuclear testing, and see exactly where the surface waters are going down, and how fast they do.
@@plabptng9 deuterium is stable and not radioactive, so i'm curious how it would be detected without taking samples and running them through a lab. even for tritium, the extremely weak beta decay would be impossible to detect from aerial nuclear testing
I've experienced this while scuba diving in a large lake. At around 20 feet the water dropped about 20 degrees from the warm(ish) water on top and the cold water underneath.
The largest waterfalls are, in fact. Underwater. An underwater lake of cold water at the edge of, say, the continental shelf drops cold water over that shelf and bam. Underwater waterfall. Just don't try to say "underwater waterfall" too fast.
Your off-peak approach is a common setup here in Australia and works well using ripple control. The device that controls it picks up on ripples in the supply current that are injected into the grid. There is also a random delay in when the circuit turns on to avoid everyone’s water heaters turning on at the exact same time. I’ve always thought it was quite a clever system.
Same in France. Don't know about random delay, but my dad's house had the heater switched on automatically from the electrical board, which offered 3 positions for the heater instead of 2: always off/on during off-peak/always on.
@@Nereosis16 Where I live in the northeast US, we don't have variable electrical rates (yet), so it doesn't matter from a price standpoint when appliances run. Thus, we aren't equipped with any off-peak scheduling technology. The only people around here who would have anything like that will be folks who generate their own electricity (usually with rooftop solar panels) and wish to use their own power rather than interact with the grid, but even that level of adoption depends on reimbursement rates. In my immediate area, reimbursement is 1:1, so it literally doesn't make a difference to your electric bill.
We also run our water heaters a lot hotter than 50*C, usually around 70*C, and we have a tempering valve that automatically limits the water output temp to 55*C or so to help prevent scalding burns.
Here in Germany these water-heaters make no sense unless you have solar on the roof. The standard is a flat rate for the whole day so the electric heaters without a container is cheaper. These may be efficient but just heating directly is even more efficient. There are variable rates but they generally are not worth it except for special setups like solar or for EVs The day-rates are so high that you will be worse off with that plan unless you hardly use any energy during the day.
In the UK we have a dual rate electricity supply in some houses with electric water heaters so water is heated at night with the cheaper rate, the second heating element is on the "always on" circuit and only activates if the tank runs out of hot water. This also applies to the electric storage heaters which essentially just heat up bricks at night which then radiate their heat back out during the day
Fun fact: I found out about how long it takes for the water to cool shortly after moving in to the apartment I'm in now. I found out the hard way that one of the "light switches" that didn't seem to do anything in the bathroom...is connected to the water heater. I took a shower the day after turning it off and it wasn't as hot as I'd like, but it was okay. It's when I prepared dinner that evening that I realized I was out of hot water and eventually figured out it was that light switch.
@@demondoggy1825 Lot's of people. You can switch it off when you don't use it or travel, or if you also have a gas water heater but keep the electric as backup, or if you're the kind of person who is afraid that you might get an electric electric shock while showering or touching the pipe when there is a fault in the water heater ( very unlikely if you have a residual current breaker, which you should have anyways because otherwise you could get shocked by any household device not just a water heater ). So it's not a bad idea. But an unmarked light switch is probably not a great way of doing that.
The GFCI in my bedroom is wired to the garage circuit, and vice-versa. *That* took forever to figure out. Since the bathroom in question is literally on the opposite side of the house. That said, my water heater stays hot when I turn it off for a 2-week vacation, as in when I turn it back on the fire doesn't need to light. It didn't 'cool off' for you. You just used up the hot water.s
I would enjoy an episode about tankless water heaters. I've had two over the years and there are certainly advantages and disadvantages. But in a family with multiple people using a shower or bath, they really come in handy sometimes. Also, I'd love to hear about recirculators which i haven't used.
Tankless water heater are great when you have more than 3 adults in the house that work during the day. Fighting over shower temp/time with two teenagers almost made me go bald. When the old tank died it was a no brainer.
I recently built a house in California and wanted to go completely electric. Also, since water is scarce and expensive, and the house is a big long ranch, I wanted recirculating loops. Turns out I couldn’t have both. All the electric heat pump water heaters say the warranty is void if you have a loop. We were forces to go with gas tankless heaters.
@@JoeBorrello is water really *that* expensive there that you have to trade the little bit of extra water use off to having super inefficient recirc loops so you spend way more energy? I’d have looked into having multiple water heaters spread throughout the house, since I would also assume your wet areas are mostly clustered.
One interesting part of the water heater that you didn't mention (because that isn't part of the story you were telling) is those things on the water pipes near the top of the tank. They are Dielectric insulated unions, which provide dielectric insulation between two dissimilar metals, which prevents galvanic corrosion. The tanks are usually steel, and the water pipes copper, so that insulation is needed between them.
I bet they're many times more expensive than a CPVC nipple, which would do the same job. And if CPVC isn't code in your area, there's also PEX , which is also way cheaper.
That would explain why the anodes aren't really meant to be replaced. As long as that insulation wasn't defeated by some ground or other connection there wouldn't normally ever be a need for it. But if a single connect could be made from the tank to any other part of the water circuit. But if the system has a ground tied to the tank through the power and it connects to any other conductive surface with a different chemical make up that the water makes contact with, then electrolysis would happen. The bimetal creates a current that erodes the metal. That's why those metal sandwich batteries called rvs have water tank anode problems. This gives me an idea for a new type of thermal battery. Thanks guys
@@tylerdurdin8069 Galvonic corrosion has nothing to do with the metal tank rusting. You will always need a sacrificial annode due to the oxygenated water continuously entering the steel tank (iron+oxygen=rust). If you read any water heater manual, they mention checking and replacing the annode rod every 6months or year). Nobody does it. I have never heard of anyone doing it. The rod may last 4-7 years, then the tank quickly fails within a year. Water heaters are disposable appliances and are not made to last. Back to galvonic corrosion. The dissimilar metals are not an issue without an electrolyte. Distilled or dionized water will not have any corrosion effect. However water quality and mineral content varies throughout the world. Effects of galvonic corrosion happens right at the point where the 2 metals and the electrolye touch. i.e. a copper fitting to a steel pipe with non-pure water inside. The effect will create a small voltage (less than 0.5 volts)
@@ecaparts "Distilled or dionized water will not have any corrosion effect" u wut. Distilled water is particularly MORE corrosive than regular water. Some types of corrosion may be less likely, but other types become much more likely.
@@ecaparts, this is interesting. My previous hot water heater failed when it was about 15 years old, precisely because the sacrificial rod was spent. (In fact, it sprung the leak at the top, where the rod went in. Whoever installed that tank apparently also didn't know about dielectric insulated unions, which meant the plumber who replaced the heater had quite the time breaking through all the corrosion at the water connections.) The tank I have now is going on 16 years old, and I've been very concerned about the condition of its anode rod. I think the main reason why nobody checks it is because there is no easy way to do that. The only way I know of is to remove the rod and visually inspect it, but many water heaters, including mine, are installed in locations where it would be impossible to remove the rod and put it back in. The work-around, I guess, is to simply replace the rod every few years, as was suggested in the video, but I'm not going to attempt that myself, as getting the right articulated replacement rod requires some knowledge about water heaters, and I wouldn't be surprised if plumbers use some sort of torque wrench to ensure it's tight enough to prevent leaking or loosening without stripping the threads, which probably aren't designed for many rod replacements. For what it's worth, when I drained and refilled my water heater last spring, I found surprisingly little rust and silt in the water I took out. So, hopefully, my water heater still has some life left in it, but I still intend to have the plumber in soon to check it out.
The amount of surprisingly useful things I've learned from this channel are amazing. Space heaters, water heaters, air conditioners... All things that I've used in home repairs. If you've got anything on basic electric clothes dryers and washers, I'm sure it'll come in handy for a lot of people too.
Here in France I have a 200 litre tank very similar to yours, but with a single 1800 watt 230 volt element mounted at the very bottom next to its one thermostat. It's on a timer from about midnight to 7am and has never left us short of hot water even with guests staying with us. They are common here and very efficient. Great video, as always. Thanks!
Your idea for cheaper electricity water heating has been in use for a while. My family has an off-peak water heater which just means it has more insulation and a bigger tank. We have a whole separate meter for the cheaper electricity at night. Thanks for the videos, I never realize some things are so simple but so smart.
@@gormster Australian here. We've always had an off peak electric hot water heaters. Just a timer in the switchboard. Has been that way for long enough for me to not know when it started.
From the Queensland plumbing standard "In hot water storage systems for residential buildings, hot water must be heated to a minimum of 60°C to prevent the growth of bacteria such as Legionella. The fitment of a temperature control device ensures that the hot water is delivered to taps at a maximum of 50°C"
@@Lazy_Tim Same here in the Czech Republic. If you use electricity for any application with substantial accumulation ability, you can arrange a special plan with the energy provider so that they can remotely switch these appliances based on the network load. You have a guaranteed total runtime per day based on the accumulation capacity and a significantly lower electricity price during the off-peak times. The advantage is that you don't have to time anything yourself, it's drived by a signal going through the power lines themselves.
From France. I Never heard of a hot water tank that is always heating water. Here the hot water tank is always connected to a relay, controlled by the electrical counter for night/day indication.
Here in the UK it is common practice to have the water heater energised during the night - for the exact reason you mentioned (ie the cost per kW is reduced) and providing you have a tank with sufficient capacity (and the water is heated to 60°c) it provides plenty of hot water for the entirety of at least the next day - so fear not - your experiment can be deemed a great success!
Indeed. Often there will be a boost switch which activates the top element only for a period of time - so if you did somehow drain the entire tank during the day and need a bit more hot water, no problem - just turn on the boost to get a bit more without needlessly heating the entire thing.
Also common in Australia. In fact, for Double Technology Connections points, Hot Water has its own separately metered circuit on a mechanical timer! Commonly referred to as "J Tariff".
I learned this last year when I got a new water heater. The plumbers who installed it accidentally configured it in "commercial mode" where it tried to activate both heating elements at once. I would get a bit of hot water, and then it would pop the circuit breaker and go cold. Thankfully, the installers came back and fixed it.
Thank you for educating me on how my hot water heater works! Though I’ve worked on mine a few times, I don’t know if I truly understood how it worked. If your heater stops working (as mine did one morning with guests visiting), it is surprisingly simple to diagnose and replace a bad element (an extremely common problem on older heaters) and now I understand why it was the bottom element that I replaced. …but, I also now know that my failure to replace the anode likely limited the lifespan of the new element that I installed. Remember, a plumber would likely charge a small fortune to replace the entire heater rather than suggest the anode and lower element for $20-40. I have also always had and actively used a timer switch on my heater but didn’t know that I should have used it to avoid peak usage hours. I only ran it 6-hrs a day but little did I know that it should’ve been something like 4-hrs in the wee hours of the morning and 2-hrs mid-afternoon. Duly noted.
You might be interested in the slightly different approach to this system we take in the UK: For a start, our water heater tanks are usually made of copper rather than steel, so there is no need for a sacrificial anode to protect them. The inner surface gets coated with a layer of copper carbonate after a few years of use (this is the green layer you find on the inner surfaces of copper water pipes), which protects the metal from further oxidation. If you have copper pipes joined to a steel tank, with both metals exposed to the same body of water, then the steel itself becomes the sacrificial anode and corrodes at an accelerated rate. The zinc or magnesium anode prevents that, but if you have no steel in the system and all the metal exposed to water is copper, this is not needed. Another minor difference: Instead of a dip tube running down inside the tank, we just have the water inlet pipe connected near the bottom of the tank. Makes manufacture easier, but accomplishes the same task of only admitting cold water at the bottom. Instead of having a pair of heating elements with one at the middle and another near the top, we usually have just one element, rated at 3 kW (13 amps) since we generally have 240 volts available everywhere. The top of the tank is usually dome shaped rather than flat, so the hot water outflow pipe is connected at the apex of the dome, with the hole for the heating element slightly to one side of the outflow pipe. Due to the curvature of the dome, the element is oriented diagonally, so it can be the maximum length the dimensions of the tank allow while still reaching almost all the way to the bottom of the tank. Because every level of the tank has part of the same heating element in it, you only need one element to heat the entire tank, and convection currents take care of the mixing between hot and cold.
That’s really smart! I have a stainless steel tank (in US) that also doesn’t require a sacrificial anode, but everything else is typical US design (in/out flow, dual-element, etc).
@@modquad18 One thing I forgot to mention before - a steel tank requiring a sacrificial anode will produce hot water with elevated levels of dissolved zinc or possibly magnesium, since these are the metals used for the anode. This doesn't matter if you're using the hot water for washing or showering - but if you are using it for cooking, then it can give the water an odd taste. Both of these metals are essential minerals for humans, but consuming too much of them is probably not ideal.
@@IwnBru Apparently the national grid hasn't realised that change either: If I measure the mains voltage coming from my house sockets with the AC volts setting on my multimeter, it clearly reads 240 volts. In fact where I am specifically it reads 242, so slightly higher. Yes, I've tried this with several different meters, and they all give the same result, plus or minus 1 volt. So unless every multimeter artificially gives a reading 10 volts higher than the mains voltage actually is, I would say that it's still 240.
@@lloydevans2900 Voltage standards are regulated at substations, at inline voltage regulators along the distribution line, and sometimes using a tap setting on the service transformer, with the intent that every customer on the circuit will see the target voltage plus or minus N% at their service meter. Can't comment on the UK, but in the US, the base voltage is nominally 120V and the tolerance is plus or minus 5%, which means anything between 114-126V is reasonable and represents normal operation. I'm in a suburban neighborhood and usually see 119-123V at the outlets year-round, depending on how much load the neighbors are putting on the shared service transformer. But in areas with long lines and seasonal loads (e.g. large irrigation pumps), customers may see averages more in the 110-115V range and experience seasonal variations.
Can't state enough how valuable I consider your channel. Learning and knowing about your every day appliances and technology is super interesting and can actively help you making better decisions when buying or repairing things as well as helping out the environment.
We're in a new home, and lost power recently. This led to an interesting lesson. We've never had a gas water heater, so I was a bit surprised to find it working just fine after hours without power. I incorrectly assumed it must have some kind of small back-up battery, but just learned about the thermopile/thermocouple that uses the heat of the water to power the electronics. Would love to see a video on those, and their potential applications.
This is also how most gas fireplaces work now too. Absentmindedly flipping on the wall power switch that controls mine during a long power outage last winter, I was shocked to see it turn on like normal once I realized what just happened. The blower fan doesn't work of course but it heated the whole house just fine.
Heads up on your water tank temperature setting. You want to set it minimum 60C or 140F. It's standard setting when installing due to legionella thriving in water tanks. Also while on the legionella topic. If you go away for any extended periods of time and your domestic water is not cycling it's a good idea to run all your taps when you get home and get all that possibly infested water out and fresh stuff in.
I cannot believe how good your videos are. They're just so incredibly topical. You break down everything you cover into chunks that are so understandable. It's really, really impressive.
One option to employ is a post-heater mixer. This allows you to have much hotter water in the tank without making it dangerous for people using it. This means that in a shower, you use much less hot water per second and can get more time out of the same size of tank. I've actually been looking at one of these because there is not actually much space between "not hot enough for safety" and "too hot for safety". With this, you can move the heater to heat "too hot for safety" but have the water coming from the hot tap be fine.
One consideration though, if the tank ever does leak or explode, you’re going to have extremely hot water blasting at you while you’re trying to get to the cutoff valve to stop the tank from refilling itself. Even without a post-heater mixer I’m a fan of keeping water hotter (you can control the mix at the tap, but manually). Not recommended if you have kids or morons around.
Post mixer is compulsory thing at least in most european countries, so you can easily put the thermostat anywhere from 65 to 90 C and still you get 55C from tap no matter what you do.
@@thedave1771 Almost never happens though. They more or less just fail by a leaking pressure relieve valve 99% of the time. The new heat pump water heaters use a post mixing valve built into the unit just fine. It helps as say 140F vs 120F is almost 50% more capacity of hot water. Maintaing the tank temp with a heat pump is very energy efficient so not a big deal, but their recovery per hour is very small so this helps them compete with natural gas or resistance heat units which have much higher recovery rates.
As a person who is effectively an intern for energy auditors, you have shed a great deal of light on topics I encounter in my every day, and that are important for people to know in general. I cannot thank you enough for this video and the many others you have made exploring how we use energy in our homes and the technologies these devices employ. You are truly a boon to any mind curious about their home, and about many devices besides. Thank you!
I have had my electric water heater on a timer for over 15 years. Never had an issue. Ran out of hot water a very small number of times. My old hot water tank lasted over 25 years using it like this for obviously most of its life. I did always wonder how the water always stayed hot all day. Thanks for the video.
As a chemical engineer grad now working in industry going on my fourth year, thank you for these vids. Mass and heat transfer is an incredibly beautiful subject and I’m really happy you’re showing it to so many people. The moment that weird and abstract equation that I thought I’d never use suddenly becomes a really amazing tool under my belt once I start asking myself how I’d go about about tackling the problems solved by this device you present. Like if I had to solve this problem, would I even be able to do it? How did they space the relays? How hard would the math be to model it vs. just iterating through a bunch of educated guesses? Is there some smart dude who figured it out beforehand so you don’t have to? Is that info behind a stupid paywall? Who the hell is Grashof and why do I want his number? Can I use this info to determine if my neighbor is trying to scam me into buying a crappy water heater or when mine breaks down? Haha seriously though, thanks! It’s refreshing, fun, and makes me love what I do that much more. Cheers mate
As one Chem-E to another, we just need to get this man into process control. Essentially, that what a smart home is: A set of simplified inputs and outputs, which are networked together to provide a central control system for common functionalities around one's house. Love you thoughts! That's my real premise: Engineering is not a degree, it's a mindset.
I wish there were more people who are taking the heat that my refrigerator(s) give off, then aim that at my water heater. If I get a Heat Pump water heater, then take the cold air that comes from it and give it to the refrigerator. Take the heat from my clothes dryer and aim it at the water heater. That sort of thing.
I have a suggestion for a small change to your setup. If you change the load switch so instead of turning off the power to the whole tank just connect the load switch to the bottom heater (so the load switch breaks the connection between the top and bottom, so the top still overrules the bottom). In this setup you will always have (some) hot water because the top element will always keep the top warm. This can help in the odd case where you end up unexpectedly using hot water in the day. I worked making load switches to control hot water tanks like this, and the electric company (who was installing these in peoples houses for peek shifting) was worried about people running out hot water. We had a more complex system where we monitored the tank temperature, but most of the time it worked out the same as just disconnecting the bottom element.
Many water heater timers have wiring for both elements (the fancy ones if have lockout timers for the top element.) It takes a bit more wiring knowledge, some extra wire, and you have to rewire the internals which isn't too difficult as you use the old wire to pull it. BUT the way he did it requires no knowledge of or extra wiring, so it's easy to try and remove when done. Also gets around code or permitting issues, or even renting.
Here in the UK most people only run their water heaters at night, they all come with timers for that purpose. I have spent many hours in the bath wandering how they work so thanks for the vid :)
Yeah, I was going to come to say that, watching him talk about disease concerns. It's literally normal in parts of the UK, especially where there's no mains gas. There's usually a timer and a switch or button to turn it on to boost during the day if necessary.
The disease thing got me thinking, isn't that like the reason why you DON'T CONSUME the hot water? Even if there's no bacteria etc, it can still stay in the heater for days and almost become stale(idk if it's the right word) and have rust and stuff.
@@odkres Yeah remember that sacrificial anode? While it isn't toxic it still fills the water with metal ions over time, and it's generally more a "better safe than sorry" practice.
@@wjcferguson It's worth noting that we normally run our heaters hotter in the uk. 60C at the heater and 50C at the tap is considered the normal safe temperature. If water is routinely standing at 40C for several hours there's a significant risk of bacterial growth. That's why it's recommended to run your hot water through all your taps for a few minutes any time you've been away for a couple of weeks, it'll get back up to a temperature that'll kill most of those nasties off.
@@odkres I don't think we ever had issues with diseases in our water heaters and we used to live in a different house for 3 months in the summer. So 1 house had "mostly" stagnant water for 3 months and the other house for 9 months (eventually the summer house got a solar water heater). But yeah, we'd never drink it. My father was an electrician (among other things) and he didn't like it if the water heater was on while anyone was taking a bath. It's a common fear from that generation.
Your expansion of my concept of what counts as a "battery" has been the biggest single change in how I view energy in all the time I've been alive. A recurring theme in your videos is how subtle things can suddenly add up to something big and/or profound, if you just stop to think and stack them up in your mind for a moment, or if you see an application that isn't always obvious. Thank you for your dedication to the fundamentals, stripping down devices to their component parts, and then building back up to an understanding of both *routine operation*, but also crucially, *unseen implications*. I will always cherish that special sauce element of your videos. From one nerd to another, thanks!!!!!
Well, every machine is an energy conversion device. And as long as you are sufficiently flexible *when* the energy is being converted, you've got yourself a battery: Solar-thermal power plant? Harvests energy from the sun and collects it as heat energy; and if you have a way to store that heat energy it can keep producing power through the night. Electric car charger? Converts electric energy into chemical energy, and usually you have at least a 14 hour window inside of which you don't care when exactly it happens. Washing machine? Converts electrical energy into clean clothes, and as long as you don't care when that conversion happens (you kind of do, because it's bad for the clothes to not go immediately into the dryer) you can store energy in the form of clean clothes. Geothermal power plant? You could (probably) draw less hot water out of the ground to let the rocks heat to a higher temperature and then get more energy at peak times. House cooling, Water boiler, ... as long as one can keep finding machines that consume, - I mean convert - significant amounts of energy and don't *need* to run at a specific time, there won't be an end to this list.
I love all of your videos. All the miscellaneous tech that we never think about, but are common in every day life. It's fascinating learning about it all and I feel smarter after each one. Also, I really wanted to say that I love your subtitles. I know it's a lot of effort to put them in, and I just want you to know that it's very much appreciated.
In regards to energy storage, i can't recall if you've spoken on this before, but ice storage for large chiller installations might be an interesting topic. During the summers, make ice during the night, when energy is cheaper and offices and schools aren't occupied, then use that ice as a heatsink during the day.
My college has this. There's basically an olympic pool worth of water in a massive tank in the basement of the main building. It gets frozen at night when rates are cheaper and the ambient air is cooler making it more efficient. Throughout the day water is circulated through and pumped to the air handlers. A student designed the system in the late 60s for the then-new building.
There's a large facility in downtown Houston that does both district heating and, more importantly, heat sinking and chilled water for the rarer "district cooling". It opened around 1980 and has run ever since.
It's been done, but with the move to green energy, the time usage rates are going to go upside down. Cheap energy will be during the day when solar power available and night energy will be expensive as it will have to come from storage.
@@hankkline7300 Yup, exactly. Assuming it was actually equivalent to an olympic pool (I do not know the exact capacity, it was just always referenced as such) that's 3750 tons of ice. For the 14 hours per day the AC was active, such a tank would provide roughly 268 tons/3.2 million BTU/hr for those 14 hours. That was just enough to cool the building on a moderate summer day given its size and energy saving features (very advanced for when it was built). There were 2 300 ton chillers on the roof to refreeze and provide additional daytime cooling when needed on hot days.
Solar PV Retailer (from Australia) here. If there is a Thermo-coupled Hot Water System in the house, I always strongly recommend a simple timer, which clicks in around 10.00AM and turn it off around 3.00PM. That way, it turns into an Energy Storage Device. Have done many, and there is no complaint of running out of Hot Water even for medium sized families. Saves a lot of $$ on bills.
TC, you never fail to make any seemingly mundane topic interesting and fun. Plus your sense of humor is right in line with mine. I look forward to every video you put out. Thank you man.
Alec must walk his appliances as a farmer walks down the isle in his chicken coup. "So, who of you will be my breakfast today? You? You? Any volunteers? No?"
I’ve had the (mis)fortune of owning three different heat pump water heaters over the last six years. Finally found one that is actually great and I keep meaning to make a video here on my channel about the whole experience. This video is giving me the motivation to actually get to filming.
You should too many videos out there about how they're such a great thing to have, I was considering getting one, but the move from gas to electric had me worried (especially when electricity prices here are well over 3x national average), I guess luckily for me the rebates didn't apply to me because I didn't already have an electric water heater, so I went with a tankless gas instead.
I live in Florida and wanted to install a heat-pump water heater. I wanted to put it in a ventilated lean-to utility shed on the back of my house but they said it wasn't supposed to be run outdoors. It was mean't to be in a basement or garage. I guess it would cause excessive condensation and rusting if it was running in normal outside air.
Wow, what happened to them? I put an AO smith in last summer. I don't get any condensate for many months of the year, so I'm hoping it lasts. I can imagine them dying in humid climates when the evaporator stays wet.
Fun fact: the name of the temperature gradient is the thermocline. The properties of the thermocline is important for many applications, one which was showcased in the video. Another important property is the warping of sound in the instance of sonar. While not impossible, it is very difficult to detect objects while using passive sonar through a thermocline.
Your delivery is goofy, which is one of the reasons I keep checking in with you, I like goofy. AND, you provoke thought on some very interesting topics. Thanks, and keep up the good work.
If you wire your timer to only switch off the lower element, you get the best of both worlds. The upper half will still be reheated if you use more than half the tank, allowing you to draw more hot water than a single filling and ensure the water you get has been heated to safe levels. You then probably want to set the temperature for the upper element a bit lower to avoid it coming on during the day for a small general temperature drop.
My own water heater has been a pain in the neck recently - this video was just what I needed to get a better grasp on the situation. I've always wondered what's going on in a water heater. Now I know. Great video as always!
Sounds like it would be worth hooking up only the bottom heater to the timer, or somehow setting up the top thermostat to trip an override on the timer. That way you'd normally only heat the cylinder overnight, but if you had abnormally heavy use you'd still get it heating back up again during the day.
Here's a tip for anyone sharing a home with 4 or more people. Crank the hot water temp to the maximum. It does make the water dangerously hot, but you will never run out of hot water. Instead of a shower being like 50/50 hot to cold water, it's like 20/80 hot to cold. A smaller volume of hot water is needed for someone to shower.
When I lived in the UK and now in Australia the water is heated by off peak electricity over night, and most days we have hot water all day. Our current heater uses a thermostatic mixing valve as you mentioned. In the UK the tank was smaller but had a boost switch for when ran out of hot water, this does not seem to be a thing on most heaters in Australia, so when you run out, you have no more hot water that day, which I find annoying, though that does not happen that often.
I've got one, but I don't use off-peak power. It's a necessity for solar-thermal when you get a run of cloudy days. Still comes out a hell of a lot cheaper than off-peak, though. Getting the system took something like a third off the power bill, even in the middle of winter, when the boost gets the most use.
Yeah, I bought my house with a 50 gallon GE hybrid heat pump heater and the cost difference is pretty crazy. The EnergyGuide sticker estimates only 1830 kWh of yearly use.
@@DLJaspah Yours must be a big one, mine is only 850kWh for a 45gl hybrid. Although mine is very new and I was very aggressive at finding the best efficiency model on the market. The sticker says $103 at 0.12¢ per kWh.
@@miavaughn2393 Guys guys, you don’t have enough perspective. Where does the warm water go after leaving the faucet/shower head? That’s right, it goes into the drain pipes. Since drain pipes carry warm water when you use the warm water, you could make a heat pump that instantly pulls heat from the lost water and puts it back into the incoming water. Add some batteries to those things that you could charge at night and you have a very cheap to operate device that loses no significant amounts of heat overall.
@@cezarcatalin1406 Nice! I feel like I'm just min/max-ing my house at this point, the cost and efficiency gains are just a side effect lol. I already want to redirect the condensation drip from the A/C to a tank to use for watering plants or something. Debatably drinkable since while it is condensation, it's also dripping from the dust-and-who-knows-what covered coils, but I certainly could use it for more than just keeping the drain wet. 😅 From the time the drain line broke and had to drain into a bucket for a few days, here in Texas in the summer that thing puts out *way* more water that I thought it would! I'm kind of curious how much water I could actually get from redirecting the intake of the off-grid van's A/C to pull from outside if I have excess power. Probably not very much, but would be worth looking into since with solar power, water would be the limiting factor for how long it could be remote...
This is the sort of extremely simple, but very clever, solution that I love. Thanks for sharing. It's really amazing how well such a simple thing as two hearing coils and filling from the bottom works
In Australia is quite common to have off peak water heating, where the water heater is only on during off peak hours, typically 1AM to 5AM, and this heats the water for the following day. As you found, it doesn’t cool down significantly, unless you use all the hot water. The off peak electricity charges are way less than standard day rates
Also very common to have solar hot water, where it only heats during the middle of the day. You size them a bit bigger and even after a rainy couple of days (with basically no heating) you still have hot water.
How about a follow up on how a gas heater works? Or if it's basically the same one on the differences. One thing I like about our at least 20 year old gas heater is that because it has an actual pilot light when we lost power for a week in below freezing temps, we could still take hot showers!
Gas water heaters are completely different in that they have a heating plate that's heated by a gas burner at the bottom of the tank and a baffle rod in a flue that runs down the entire middle that works like a heat exchange that vents at the top, with a singe thermostat connected at the bottom of the tank that controls the gas flow to the burner. They're fairly efficient but I think they can run out of hot water faster under heavy use. They are indeed handy in power outages though, because nothing runs on electricity, and the igniter is usually piezoelectric. We used to have one in our old house that was there before we moved in and had been in for 15 years or more prior to us using it for least 5 more before replacing it. I'd still have one if we got natural gas in this area. If you keep the anode rod changed out and flush the tank every so often, they'll last for many years.
A third type is the water-heated water tank that is heated by the circulated water in a radiator based home heating system. Such a water tank has thermostatic valves instead of switches, while the separate home heating system keeps the circulating water at 70° to 80° C (160° to 175° F), which is then directed wherever heat is needed. That home heating system can in turn run on any heat source from piles of chopped wood to excess heat from a nearby nuclear power plant. Though so far I have only enjoyed intermediate solutions like bio fueled power plants and a coke fueled home system from the 1940s.
Not to mention that electric water heater elements (especially the lower) scale up and shed calcium into the bottom of the tank eventually the scale covers the lower element causing it to overheat and burn out, and seeing as how the lower element does the majority of the work(didn't know that part about only running one element) it is a major problem. And that little drain spigot doesn't do anything for removing the scale. From what I have seen a water heater will scale up long before the anode rod is used up.
The tank target temperature of 50˚C made me do a double take. Here in Norway we usually run our tanks quite a bit hotter. The thermostat on the tank has a range of 70-95. If your tank temperature is under 70˚C you need additional measures to prevent legionella spread (e.g. increasing the temperature at regular intervals and flushing your pipes)
We do something similar in the UK, with the tank usually heated to 50-65C, and the controller periodically runs a “legionella cycle”, which brings the temperature up for an hour or so. In reality, you are actually perfectly fine to keep water in the tank at 50 without the legionella cycle, as long as the water gets used. Legionella requires *both* a certain temperature range and stagnant water to multiply. If you go through your hot water regularly, you won’t have legionella problems.
@@RussGreeno is your water supply a well? My water temperature has been about 125f (51c) for over 40 years. My newer heater is 132 (55c) at the tap. Plenty hot. The US standards require a small amount of chlorine or a couple of other chemicals in city water systems..... I don't know how yours and other countries treat city water.
My observation as well. Here in Finland we have our tanks 55˚C+ to prevent legionella, and nightly water heating is the norm. So even though the water temperature drops during the day, 55˚C should be enough to kil all legionella in a few hours at most. Now I think our water heater is dumb and only does what the thermostat tells it to do, so I think our water heater does not periodically heat to super hot by itself.
@@Aethid exactly the same. Heat pumps get less efficient the hotter you run them. Our heat pump brings the water up to 55°C nightly. Then weekly the legionella cycle runs and heats the tank to 65°C off peak. Most legionella bacteria will die in less than a couple of hours at 55°C, the 65°C just makes sure it's good and dead.
Thank you technology connections and thank you to his patrons for supporting him financially. I get a lot from his videos. Also to subscribers for having good taste. Thanks.
Here in Australia, when we had a new water heater installed, they offered to install a distribution board integrated hot water timer for no cost (it was a simple mechanical one, but if we wanted a smart home integrated one, it was not that much more (can’t remember what the price was, so I don’t want to speculate and be wildly out given the recent price increases here) we have ours set up to run during the day as we have a rooftop solar panel array, but it has made a big difference to our electricity bill.
I got a new house, finished construction December 2019 in Tasmania. No timer. It was a 3.6kw single element 250L tank. My brother in law is a plumber so I asked him to replace my 3.6kw element with a 1.8kw element. My morning shower would trigger the element to run for about 40min when my solar was only generating about 1.5kw. So I was paying peak electricity prices for half my hot water. Now it's a smaller element, it runs twice as long but my solar mostly covers it now reducing my morning shower by about 50c/day.
This is very interesting. No, that’s not a strong enough word. This stuff is some of my most looked forward to content. Learning about the little engineering marvels in my life is the highlight of every month or so. Thank you for this. Your interests, particularly as of the past few years seem to perfectly match up what I’m curious about, and you do an amazing job explaining them in detail but at an understandable level. I need like a full show with you as host explaining all the household devices we don’t think about. On the topic of water heaters, I’m glad your take is that tankless isn’t worthwhile in many situations. When I heard how many BTUs a tankless water heater burns and why they often need to be gas, I was pretty shocked. My household does tend to take long showers so I do run into cold water issues when shaving my legs or something, but all in all, a tank water heater is still ideal for my situation. Maybe just a slightly bigger one. And maybe a hot water recirc loop so I don’t have to wait a minute for hot water. And maybe a heat pump water heater to take advantage of that technology. Hope you cover some of those topics in future videos if you have a chance. Edit: the water stratification aside was some of the most interesting thermodynamic physics I’d ever learned. I learned about the huge amount of heat water used in high school and even did the coffee cup calorimeter experiment at the time, but the numbers didn’t really make an impression on me. And also the sacrificial anode detail - I’d heard about those but hell if I knew how they actually preserved the life of the tank. Oh and I didn’t know they were so well insulated - I guess it makes sense that they should be but I always thought it wasn’t enough. Guess appliance makers have had decades to perfect these things into the cheap and effective things we don’t think about now. Speaking of heat pump water heaters, it would be pretty damn cool to integrate them into other heat managing appliances. Seems like it could be a good heat dump for AC systems. Or maybe could even be used as a large reservoir of heat for heat pump heating (I tried to use fewer “heat”s) for those particularly cold nights or when solar power or time of use electricity would make sense. I could imagine storing heat in water could be a lot cheaper than storing it in batteries if you have solar and excess energy in daytime. Sadly I haven’t heard of any kind of integration on this level, but it should come to market at some point given the rising prevalence of solar equipped homes. I can’t imagine the actual connections would be difficult - just the management of heat transfer and thermostats and schedules might be tough with existing dumb electronic controls. Maybe it wouldn’t be worth the complexity or cost, but something tells me storing excess energy during the day as hot water for use in nighttime heating and dumping AC waste heat into hot water would reduce energy and battery demands by enough to make it worth it. Someone correct me if I’m wrong. Before this video and the one about using a well insulated home as a thermal battery, I’d never thought about the whole potential of heat storage, but when we have so many power hungry appliances dedicated to heating or cooling the air and water in our homes, it makes a lot of sense to think of heat storage as a viable method to reduce consumption.
Along the same lines, hot water heating is used in a lot of large residential and commercial buildings. Pushing hot air through large ducts all over the building can be challenging. It results in lots of heat losses and it's difficult to control the heating among the many zones. Adding a heat exchanger in each room with a local thermostat makes it easy to heat or cool the air just as it enters the room as desired. The water pipes are much smaller than air ducts, can carry much more thermal mass, and are easy to insulate to avoid waste. Just like your hot tap water, you can use heaters, heat pumps, and tanks to heat/cool and store water for your home heating and cooling whenever it's cheapest/most efficient and use that whenever a room requires it. Heating in particular is great because you primarily need the heat at night when electricity rates are typically cheaper and don't need it nearly as much during the day. With solar water heaters, you can even charge up that heat reservoir during the day and use it up at night, rather than having to store that energy in batteries. Our oceans naturally do this, which is one reason why coastal areas tend to be more temperate with smaller day time temperature fluctuations. When it comes to using sun, wind, and other renewable sources of energy, we can take a lot of inspiration from nature, which has been perfecting its usage of these energy sources for millions of years.
The whole "heating water over night" thing is very common in Europe. Here we set the water to be hot by 6am (or whatever time your power becomes more expensive) and have a lagging jacket over the tank to keep even more heat in. If you have a big family that showers in the morning you might set the heater to come on again for an hour or so during the day to top off the hot water for the evening. I was surprised to hear you talking about it as a new thing.
Most people have a controller where they can schedule on and off times for the whole week. And these are quickly being taken over by smart controllers that you can control from anywhere. Our Tado detects when I'm home and turns the heating off when I leave the house. And i can schedule in as many on/off cycles as I want for both the hot water and the central heating. I think this is very very standard in UK so I too was surprised at how he has had to set up a little box to control the electricity.
In the US, power is cheep especially when one take into account transmission costs. Most placed in the US more of our power bill goes to maintaining the grid then to generating the electricity. It is only in the last 10 years that there has been the economic incentive to meter by time of use, and it took installing new electrical meters to make it happen. Prior to 2012 there would have been no reason to do this at our house because electricity cost the same no matter the hour.
@@Fluxkompressor Yeah, I was about to say this. Here in Hungary it's called "tariff B", "switched power", or "nighttime power" by older people. It has quite a big price cut compared to the regular price, and it's for water heaters only AFAIK. Bojler eladó.
Every single time I end up this on your videos I am pleasantly reminded that you are one of my all time favourite UA-camrs. Informative, entertaining, relaxing, and fun. 11/10
Gas heaters have one major advantage over electric heaters: they're cheap to run in the US (usually) because natural gas is a byproduct of oil extraction.
From what I've heard, besides the cost factor which is depending mostly on where you are & the current geopolitical situation(s), gas heaters can do "on demand" heating. It's not verified facts though so feel free to tell me it's not true :p
@@thibauthanson7670 I'm just one person, but I can confirm that even just turning on the hot side of any faucet even for a few moments I can hear my jet engine... er I mean my gas water heater kick on for a couple minutes heh and it was just replaced within the last 2 years...
I'm excited for that video of home electrification. Watching your videos on heat pumps is what got me to push for my wife and I getting a heat pump a few months ago when we needed to replace our 20 year old furnace and its been great. Personally as someone who never was a big fan of setting up fancy on off schedules for furnaces I've enjoyed the fact that the company recommended that you just pick a temp and leave it there for the heat pump.
00:29 🛠 Conventional electric water heaters have two heating elements (upper and lower) with the same power rating, along with two thermostats, preventing them from running simultaneously to avoid overloading the electrical supply. 04:41 🌡 Cold water enters the tank from below, pushing hot water out the top due to differences in density, creating a sharp boundary between hot and cold water. 06:32 ⚡ The lower heating element kicks in when the cold/hot water boundary reaches it, heating the water as it flows into the tank. 08:52 🚿 The top heating element kicks in once the tepid water from the lower element reaches it, providing an extra boost to the water's temperature. 10:20💡 The "1st hour rating" of a water heater refers to the amount of cold water it can bring to target temperature in one hour, combining energy input and stored hot water. 14:06 🌪 Using only the top heating element allows for faster heating of the water at the top of the tank, extending the availability of truly hot water. 16:30 🔋 A well-insulated water heater effectively acts as a battery, retaining heat for extended periods when not in operation. 18:27 🌡 Hot and cold water inside the tank exhibit minimal mixing, allowing hot water to remain at the top for extended durations. 19:54 💡 Conventional tanked water heaters can play a significant role in energy management, especially when operated strategically during off-peak hours. 20:47 🚿 Tankless water heaters may not be the best choice in all situations due to their high power requirements and inability to store energyfor later use. They may be more suitable for homes with severe space constraints.
In Australia quite a few electric hot water services work like that. Only reheating at night. I remember at a previous house there was actually a button on the power meter that could force the heater to heat water, albeit at the higher electricity rate.
Just had to replace two this week. Your video comes perfectly on time 😄 One froze from the bottom (makes so much more sense now !) increasing the pressure to the point of not only popping the pressure valve but also cracking the top and spitting water everywhere on the not so conventional electrical connections... It was... majestic.
Here in Australia it is very common to have our hot water systems using off peak electricity, which generally turns on around midnight and is off during the day. We don not have a bypass switch. I live in a rental property where 5 single bedroom units are serviced by 2 parallel single element hot water systems each with a similar size to yours. Some of the units have 2 people, so 260 litres of off peak hot water provides for 7 people. The only time we ran out of hot water was when the element failed in one of the tanks.
Very similarly in my country in Eastern EU - a decade ago it was even outright called "night electricity", it is a bit more convoluted nowadays but the idea in essence is still the same - the switch is actually on the provider's(!) side (thus gaining an extra ability to do something with the extra supply), which gives 8 hours of electricity per day, 6 of those outside of peak hours, and the minimal switching time is at least 15 minutes. This system is on a separate circuit and is billed separately of course (cheaper than the always-on, on-demand circuit everyone is familiar with), and is widely used to power water heaters. This works exactly becase as Alec said, they are batteries - they don't need to be turned on immediately just because they dip below the usual values by a few Celsius degrees, as long as the thermal mass is large enough for the usage rate.
@@AkosJaccik yeah it's called controlled load in Australia. It's because the coal power plants cannot shut down and they have to maintain turbine speed so they can ramp up quickly next morning. Sometimes the power during night is sold at loss for the spot price.
I am from Europe, specifically from the Czech Republic (a country between Germany, Poland and Austria). What you do at home has been common here for about 60 years and practically everyone has it, with the exception of those who heat water with gas. The difference is that they do not control themselves when the water is heated, but the heating is turned on remotely by the electricity distributor. It is a condition for obtaining a more favorable tariff. The basic tariff reduced in this way provides 8 hours of cheaper electricity for about 2/3 of the price every day, which can be used for anything (not only for heating water). It is divided into two blocks, usually 3-5 hours in the afternoon and the rest at night. I'm not aware of legionella issues. It is recommended to set the boiler temperature to 80 degrees Celsius for a few hours at least once a month, but no one follows it. So your reasoning is correct - it works :)
I have installed a few tanks and replaced elements in them, never gave it much thought, but you gave me a little insight in why they are the way they are, and replacing the anode does really help with longevity
In Britain traditionally the water heater design is a bit different; both elements are connected to near the top of the heater; the 'long' element is traditionally used for Economy 7 off peak use and does the job of the lower heating element, and the top element is for topping up if the hot water may run out; there is often a 'boost' button that turns the top element on for one hour. Because heat pumps are much more efficient they are now used a lot more, but the temperatures are lower and consequently the tank needs to hold a lot more water. In many instances a traditional heating element is scheduled to turn on once a week to get the temperature of the whole tank above 60 degrees for protection against Legionella.
This is great! I always knew about the top and bottom strategy but didn’t know about the “chase” effect. You should consider getting a tank blanket too which installs in minutes to boost the insulation.
This is brilliant stuff. We previously had a hot water tank but I'm unsure about whether or not it had its own heating element, because we also had a gas boiler. As far as I understood, we had to turn on the boiler's hot water switch, which would run hot water up to the hot water storage tank (big insulated tank on the upstairs floor, no space for it downstairs) then gravity would bring that water back down to the taps downstairs. Any hot water left in the tank would slowly go cold over time. We have 3 people in the house, and I don't think a water heater such as the one in your video could keep up with the demand. We also felt the extra water pumped up to the tank that was left unused was a waste of energy. There was the logistical issue of the piping necessary to take the water upstairs then back down. There was also the issue of the tank taking up a bunch of storage where we needed space for other things. Finally there was the issue of water pressure; hot water and, actually, cold water too (we had a cold water storage tank sitting above the hot water one) only had about two meters of gravitational potential energy, and while it was plenty to wash your hands with, it really sucked for showering. So we switched to a combi boiler and stripped all the tanks and pipework out. Now we have mains water pressure pretty much on both taps (I _think_ hot water running through the boiler loses a little pressure.) Hot water takes about 10 seconds to travel through the boiler and to the furthest pipe (shower.) No more turning the boiler on and waiting 5 minutes before the tank had enough heat in it. Also we converted the tank room into a storage area. I think it was the best decision we could've made.
In France, the water heating during off peak power generation is standard since 3 or 4 decades. The national operator, EDF, send a signal in the power line to tell your water heater to switch on or off. You can use that to do things like charge an electric car too. Our power being mostly nuclear, it's not easily throttled. The sacrificial anode blew my mind, great tip !
We recently upgraded our heating oil furnace to an air to water heat pump. That same heat pump also heats our water boiler now. It has no issue bringing it up to 50 degrees. Would be cool to see a video on those.
I had to change the heating elements several times over the years plus a thermostat. This video does a great job explaining how these water heaters operate. 👍 Stay well, Joe Z
This was fascinating. I've taken this thing sitting in the corner of my garage for granted my entire life. It sparked my interest in how gas water heaters operate. Always love the uploads, much love, take care.
I own the German Version, on 380 Volt in Amsterdam. I did the same what he did, mine is parallel elements too, only a bit more complex on the electronics, second element is only used when needed. It can produce 24/7 hot water... Same tech, 120 Volt is not practical, you need a better grid, sorry.
We just installed a new heat pump-equipped water heater in my parents' house and I'm definitely getting one for myself when this tank I have goes. It uses like 1/4 the power! More pumping, more now! Also, with your strategy of using the tank as a thermal battery, I found an accessory at my local big box home improvement store that is called a "hot water tank booster" - it allows you to run your water heater at max temp, and then diverts some cold water into the hot water output lines to bring it back to a more palatable temperature. This would allow you to stretch your hot water supply even longer in your situation!
That's definitely interesting. You could set the tank to 90°C, mix it down to 60°C to keep your warm water supply at a steady temperature and to increase the tanks virtual capacity by 50%
I love my heat pump water heater. I live in a cold climate and replaced an oil fired heater with it. No heat leakage through the flue pipe, this thing barely runs. I have it in my basement which is cold, but I have a wood burning furnace that leaks hot air down there and I have noticed no difference in temperature this winter. I was afraid it wouldn't be able to keep up and would run a lot, but that wasn't the case. If I powered it by solar I would install a tempering valve and set it to run during the day as often as possible, but my solar setup is off grid, running my chest freezer, refrigerator, and fishtank (It's tough keeping the snow away and getting sun in the winter)
Here in Australia it is a legal requirement whenever the hot water system is installed or serviced to fit a tempering valve. The difference between 50 degree C and 60 degree water when it comes to burns/scalds is significant. Bonus that it makes your hit water system "bigger".
This was awesome, thank you. Years ago when I was in a large house, I added a 50-gallon very squat tank with absolutely no insulation whatsoever. And then I let the cold water fill that tank and just kind of sit there in the ambient air of the crawlspace, before it went into the actual water heater. This had a sizable impact on the energy used by the water heater. Of course that preheat was not entirely free, it was sucking heat out of the ambient air but it sure did make a difference.
Great job presenting the battery aspect of the water heater. I installed a 70-gallon natural gas water heater in my home when I built it 22 years ago. When the gas water heater died, I replaced it with an electric 50 gallon, 5500W, WiFi controlled water heater. I operate the water heater at 140 degrees during super off-peak times (10am - 3pm) when the cost of power is only 3.3-cents per kwh for 6 months (winter) and 5.2-cents per kwh for 6 months (Summer). I use a mixing value at the water heater to bring the temperature down a little so that it's not too hot at the faucets. My wife and I typically shower between 6am and 8am. There is ample supply of hot water the next morning for showers. It is more than 100' to the master shower, so I use a recirculating pump to move the hot water to the shower. The pump is connected to a smart outlet that is controlled by Alexa. I simply tell Alex, "Alex Hot Water" and the pump runs for 60 seconds. Since converting from gas to electric and using the tank as a battery, my gas bill dropped by an average of $50 per month. My electric water heater measures the power consumption so I can calculate exactly the cost. Last year I averaged $7.23 per month to run my water heater. That's $513.24 per year savings.
Here in the UK, in London, I switched from an old tank to a tankless heater. We are very severely contained when it comes to space, and the tank couldn't fill a bathtub. There might be bigger/better tanks, but for you to have an idea, it was likely half the size of the one in this video.
Yeah tankless is absolutely a necessary option for space constrained apartments. But some people are drooling over them as if they where a mew shiny thing that should replace all existing heaters... And that's just not the case for americans in detached homes.
I'm honestly tempted to go tankless in my house, there's bo baths just electric showers now so no need for the tank and gives us an extra 3m^2 in one of the bedrooms
I use tankless because of legionella concerns, and the fact that many days we don't use more than like 2 gallons of hot water, while on other days we use tons of it.
thanks for another great video man. myself having a background in electrical and hvac work I usually have a good idea of what you’re going to make videos like this about, but its the way you do it and the little details you add that always keeps it interesting and make me think in new ways. bravo sir
I just enjoy learning in depth info about how the mundane objects around my house work. I love these types of videos. You're always so thorough and I appreciate your work! great job Alec!
I love how you can take something so simple and make an hour long video about it. Your videos are not only entertaining but educational as well. Thanks!
In France, we have switches that know when the electricity is cheaper (my understanding is that the electrical company sends an electrical wave on the lines to activate the switch). These switches are commonly used to switch on and off the cumulative water heaters. There's really no issue whatsoever for diseases as long as there is power at least once a day.
We have the same thing in the UK for "economy 7" homes. They turn on very late at night until the early hours of the morning when energy is a little cheaper - great for heating a tank of water, not so good for heating the rest of the home during waking hours.
That's true. So long as the water gets over a certain temperature for long enough the legionella bacteria will be killed off. If you happen to have any coming in during the day the short time at a lower temperature isn't long enough for a colony to grow significantly. Any that is there will be killed off by the nightly cycle long before it can make you sick.
Thanks, a few comments. When I was younger and had teenagers taking long showers every day, I made modifications to my water heater to improve recovery time. Essentially, I doubled the power supply to the tank and made a few internal wiring changes so both elements could operate independently and simultaneously. Special care was taken to ensure that no portion of the wiring inside the tank was ever overloaded. The result, a quicker recovery time. Today I am back to normal with a conventional electric water heater in our downsized empty nest. Now, I am participating in a pilot program from my local public utility. A controller has been placed on the power feed to the water heater. This allows the utility to turn off my water heater (along with other participants) at will remotely and minimize demand on the grid during times of high demand. Because of the tank storage, I am never short of hot water. Finally, I employed a tankless water heater in a secondary home that was used mostly on weekends. This got rid of the standby losses from a conventional water heater when the house was unoccupied.
Letting the power company control your water heater sounds like a great idea until they or the government steps in and you can't turn it on even though you own it. People have already ran into this issue with the thermostat for their heating in times when people couldn't leave their homes due to snow.
@@GrandNebSmada Yup! They are doing the same thing with electric cars. Cars only make a small percentage of the world's Co2 emissions. It's got nothing to do with the environment and everything to do with control.
@@GrandNebSmada the wiring is in your house. You own it. Modify it to create a bypass switch for the water company's switch. No issue. If they really want control, they need to shut down all hardware stores. Call me when you see that happening.
The only reason I still have an electric tank in my house is because of the reduced rate offered by the power company for installing one of those relays.
@@GrandNebSmada what's better? they essentially turn down your thermostat to keep whole whole grid up, or have to start rolling blackouts to keep the grid up.. meaning NO electricity/hear for various periods?
FYI: You're losing more heat through the non-insulated hot/output pipe than through the whole whole tank. Because as you've said hot water rises (and copper is a great heat conductor). So if you want even better storage and hot water at the tap faster and efficiency then insulate your pipes! Plus you can measure the over-5h temperature drop after to verify how much of a difference it made, and more content for videos.
ever heard about legionella? hot tap water pipes may not be isolated. this creates the legionella bacteri to grow fast. the boiler should be 60 celcius to prevent his. tip to prevent to much loss from the hot output pipe ! let it bend down direct at the boiler 1 foot al least the hot water will not go down and stays in the boiler. ps boiler means the tank !
Ok... this sat in my to watch list for quite a while, knowing it was going to be clever but unconvinced it was going to be sufficiently so. I finally got around to watching, and I am happy to say that this far exceeded my expectations. Thank you!
Your channel is why I work in hvac now instead of being like homeless or dead or something. Thanks for that!
You fell so in love with the refrigeration cycle and space heater nonsense because of him that you made it your career, that's awesome.
HVAC means you will probably be dead before you are homeless..
Honestly, I think this channel does a lot to dignify a lot of jobs folks looked down on. When you start to understand how fascinating appliances are, it’s easy to respect the folks who work on them ;). HVAC is pretty nifty stuff, imo.
This is the magic of the "edutainment" side of UA-cam. So many channels I watch have comments on random videos that say "thanks for getting me interested in X, it's now my job/field of study."
+++++
I love how this guy can look around his house, point to literally any random thing like a light switch, toaster or hot water heater and give the most in depth and comprehensive explanation about it.
That is nice 🙂
And make it interesting
I agree. I think that he could make a great video about ordinary table forks.
We must discard evil and store up good. Those who do not may be reborn into this world.
... and make it interesting to listen to.
I just now learned about sacrificial anode rods! I wish I had known about them when I bought my house. Everyone always told me you just let the tank rust and replace it when it starts leaking (~10 years). First you had me ditch my dishwasher pods, now this! When I started watching your channel, I had no idea you would be saving me money! Great stuff!
I only recently found out about them. I only really saw them being used on seafaring ships, since the dangers of even galvanic corrosion are far more impactful when you're trundling across more conductive saltwater. Of course... considering that softeners _literally use salt_ as a way to filter out material junk that gets into tap water... I probably should've put two-and-two together by now.
Most will remove the rod as soon as they install the heater. They tend to give off a rotten egg/sulfur smell, especially when new.
@@JrGoonior I have never heard of removing an anode rod on purpose.
Must be in certain areas...
Need to watch those old episodes of "This Old House" they talked about them just about every time there was anything related to a water heater mentioned
Most plumbers will tell you to leave them alone because after years of being in the tank, they can become stuck and you end up damaging the threads trying to unscrew it. Plus they get to sell you a new hot water heater.
I know this is not a DIY or repair channel, but this video actually pointed me in the right direction to diagnose the cause of my short hot water supply. I have a 55 gallon water heater that would run cold just handwashing dishes or during anything but a quick shower. Additionally, I was getting bad smells from my tank. After watching this video, I realized that it was entirely possible I was only running on the top heating element.
Sure enough, I had 240v going to the bottom element with no current draw. Resistance measured in the kiloohms.
Thanks for inadvertently saving me a small fortune in needlessly replacing a water heater. $30 and I'm able to wash dishes while doing laundry, then go take ahower!
Damn I gotta whip out the meter in my closet now 😂
what was the bad smell tho
@@aduantas sulfur reducing bacterial build up in the sediment that wasn't getting killed due to the bottom half of the tank never heating up. I took the time to remove as much sediment as I could while I had the lower element out. Apparently, flushing with the bottom valve doesn't do much.
@@guitarstitch No, unlikely. The bacteria would usually build a biofilm that just remains when you let out the water :(
Check/replace the anode rod as well. Good time to do a good overall "tune up" while you're at it.
I built water heaters like this once. This doesn't matter, but the foam is injected with the lid off at just the right amount to expand by the time the lid is assembled on the line. The extra holes in the lid is just a multi-use design for many different tanks, such as tanks with multiple fittings for dual zone or aux floor heating.
The extra holes can also be used for additional anode rods. Most HW heater models are priced by warranty years (6, 9 or 12 years). The warranty correlates with number of rods. Save some $$$ by buying the cheapest unit (6-year) and install two more anode rods yourself (get magnesium). That should give 12-years protection. Replace the rods every 12-years and you 'll never need a new WH. I did this in 2013 and am due for a change out next year.
Chiming in from France: it's completely common and very widespread here to have heaters only turn on during hours of lower cost power. There's a system that allows the power company, via the power meter, to send a signal to the heater to turn it on or off (and different neighborhoods are turned on at different hours). I guess a reason for all this is that France uses a lot of electrical water heaters, thus it's important to manage their load on the grid.
I second this, I have actually never seen a water heater that runs all the time
Same here in germany. Though nowadays you'd use your excess solar power to heat the water tank rather than letting the energy feed into the grid instead of getting a dual-tariff energy plan.
Don't france use something like 80% nuclear power? I mean they should have nearly unlimited electricity.
Also in France much of the electricity is nuclear, and there is a limit to the amount by which one can throttle down the power of a nuclear reactor; if consumption would go down too far at night, they would need to entirely shut down some reactors and start them up again later, which is very costly.
Dutch and came here to say the same thing: the only electric water heaters I've ever used had built-in functionality to only run during low power rates. At least one of them even had a timed override to let/make it run with high rates 'just this once' if you needed extra hot water for some reason. Once the timer ran out it would just reset to using low rates power only.
Late to the comments, I live in Japan with a water heater designed for rate metering and families. It heats the water to 90c during the night and saves it in a giant outdoor tank, distributing the almost boiling water to a reasonable pre-set temp by mixing It with cold water, essentially storing “hot water concentrate” to use to make way more “hot water” than it could ever store - providing enough hot water for 4-5 people for the whole day with some buffer. A control panel lets you ask to make more on demand (guests), and also, separately, manages filling and reheating bathtub water for bathing. It uses 9-12 KW of very cheap power at night, not drawing power the rest of the day in normal operation. This system was installed in ~2006.
A similar system can be used for solar heat.
Power is still cheap at night in Japan? That’s cool.
Japan seriously lives in the future. Everything is ass backwards in my country.
こんばんは (here in TX anyway). 90°C, that's pretty toasty. Talk about super-instant noodles with that water. 9-12 kW is a bit of usage, but hopefully it's not having to run terribly often. Good you have gotten almost 20 years of usage out of it; sounds like a pretty solid system.
Japan is as futuristic as the TV promised
As a mech engineer working in industry, I have to say I love your channel. Sure we have understanding of the mathematical concepts in these vids but things like this I had no idea about. Please don't ever stop making videos like this.
I was compelled to give a water tank analysis video a like. Wrap your head around that! 🤔
@@IllusionSectornow that i realize this video is just that makes me think lol 😂
So true. They teach us how to do the math for all of these systems and never even teach us how they work.
I cannot believe how good your videos are..
Nice
Good job
Good job
nice
completely agree, very good research was performed prior to production :)
They are called Twin Element hot water tanks here in Australia, and are marketed as such. They don't seem to be that common here. The majority are single bottom element types, probably because of our generally warmer climate. Yes, tank stratification is an interesting topic, it made calcs in my recent whiteboard video on heat pump hot water tanks pretty much just a guess without knowing the actual water flow rates and in/out temps.
Fancy seeing you here, EEVblog.
I've never seen twin element hot water heater where I live (Norway) and our tap water is around 4-5c most of the year. This is yet another weird american thing I bet.
They are common in the UK since the switch from vented cylinders (which are supplied from a header tank in the attic) to unvented cylinders that are connected to the incoming water main supply. The heating elements are often used as boost heaters as they tanks usually have an indirect coil carrying hot water from the central heating system which heats the water.
They are known as immersion heaters in the UK, often abbreviated to 'the immersion' and they are almost always on a timer and we don't have huge outbreaks of legionnaires disease.
Two elements is pretty standard in Canada.
Here's an idea. Set the top thermostat to 45C, set the bottom thermostat to 55C, then put that contactor in series with the bottom element. So now the bottom element heats the entire tank to 55C at the cheap rates and is then disabled. The top heater doesn't do anything at all unless you run completely out of hot water, but is still able to kick in if necessary.
18:05 I discovered this by accident, we went on holidays for two weeks on summer and we turned off our water heater, when we came back, at the following morning both my parents had a shower and later at night I did, and I've noticed that after five minutes the water was getting unusually cold, turns out we forgot to turn on the heater, and it still had hot water for almost 3 showers, only being FOURTY (40) litters (10,5 gallons) I was amazed
I just changed my anode a few weeks ago. A plumber let me in on the secret after a water heater needed to be replaced in my house years ago.
Couple of things to note: If your water heater is in a space with a fairly low ceiling you may not be able to get the original factory installed anode out without cutting it in half while you remove it. They are quite long. Easy job for an angle grinder, might be difficult to do with a hacksaw! use some vice grips to hold the bottom half and stop it from falling back into the tank. You can buy flexible ones to replace them for these situations. Every 5 years is a good rule of thumb, but this does depend on your water quality, things like chlorine and mineral content will affect the rate of corrosion. When I swap the anode I write on the side of the tank with a sharpie the date I did it so I can refer back to it. At 5 years mine still had a good bit of life left in it but I swapped it anyway because I was already that far into the job. You might need a hefty 1-1/16" socket to remove the anode and sadly the factory will usually tighten them down super tight, the first time I removed mine I needed to use an impact gun to shift it, you might think a breaker bar would work but water heaters are usually not fixed down well enough, you could end up damaging something.
If you plan to do this you need to turn the water off and drain the tank. You might think you only need to drain a tiny bit out but remember your output is connected to the house, if you're in there with the anode out and someone opens a hot tap upstairs gravity will allow the water in the pipes to drop down and fill the tank. Make sure you drain plenty of water out. You might as well drain enough to remove any sediment which is good practice anyway - some people would say to do that annually.
Even if you have to buy the right socket - anodes cost around $30. Compare that to the cost of new water heaters... with installation, removal of the old one and any damage they do when they leak? could be a 4 digit number pretty easily. Use this math to convince yourself or others that you're actually saving money when you go buy an angle grinder and an impact gun.
fun tip. The drain valve on most modern water heaters has a thread that allows typical garden hoses to connect to it, this can help simplify the draining process so you dont need a lot of buckets.
I would add to this that for those of us with water softeners the anode can be consumed in as little as a year due to increased conductivity of the sodium ions. Myself, I installed a permanent electronic anode which can be transferred to a new water if needed.
@@shawnbottom4769 what is an alectronic anode? Sounds interesring!
@@sorin.n Maybe he means the kind of anodes that are popular in Europe: a titanium one (that is not consumed) which is maintained under a small voltage by an electronic controller. It uses the magnesium in the water to protect the inside. (or it is sometimes coupled with a pre-installed magnesium anode, but the magnesium does not escape because of the constant small current in the tank.
It is generally equipped with a small battery to maintain the magnesium/calcium in place, because in Europe water heaters are mostly powered only at night: a signal sent every evening and morning over the wire from the electricity company put/cut the power when the tariff changes.
good points, another is to swap out the cheapo plasticko drain valve to a ball valve which moves a lot more water, like just 10 seconds wide open cleans out any bottom sediment, adding a quick attachment snap on ( garden hose ) makes this maintenance job easy.
@@vassili_ thank you!
I don't know if anyone's ever said this before, but THANK YOU for making the captions line up exactly with what's being said (in addition to sneaking in a haha funny or two)! I hate having to pause to read frame-long walls of text that aren't even being spoken, and since I use captions for the sake of auditory processing, I can hear all the minor mismatches and just end up irritated. Thank you for doing our eyes and ears a service!
Yeah, you'd think UA-cam auto captions could line up perfectly since they have the time stamps of the audio, but I guess it's not a high enough priority
Not just subtitles -- which is impressive enough tbh -- but *good* subtitles. Alec spoils us.
Yes, I second this
I agree, spoilery subtitles are the worst (the ones that race ahead of what's actually being spoken)
I inspect failed water heaters for a living. You happen to have one of the most reliable models I've ever seen. I've seen some of those GE (which were made by rheem) go 20 years.
Really? Whats the best gas version these days, please? Mine went kablooie rather spectacularly....thanks!
Are the ones you encounter mostly electric? Here in Germany we generally have oil and gas heated tanks and they mostly fail because of rusting and then having a hole in the bottom but the ones I know of are at least older than 15years, which is the mean lifetime given by the manufacturer.
My 40 gal water heater was 24 years old when it finally absolutely needed replacing in 2020, but I bet anyone who knows water heaters would've known it needed replacing long before I found out. Looking back at the symptoms, I think I let it go about 10 years too long.
Is 20 years a long time?
I'm not sure I've ever seen one less than 20 years old.
Plumber here. The oldest functioning electric water heater I've seen was 37 years old. It had never had any maintenance and still had the original thermostats, elements, and anode rod (which was completely gone for most of that time). I didn't recommend replacing it. Why not? Well the reason it had never leaked is because it happened to have a perfect glass lining from the factory. The inner steel tank is sprayed with molten glass, and usually that coating isn't perfect, so the anode rod helps protect any exposed steel from corrosion. But once in a blue moon, a tank leaves the factory with a perfect glass coating. This was one of those, and as such it will never, ever leak. So I left it in place!
As a plumber, I have to say this was a great explanation of operation and details of design. If you get the chance, pull an old thermostat and high limit off an electric tank so that you can see how they work. They're very simple but interesting as well.
I have recently been wondering exactly how it refills and heats without diluting the already-heated water. Neat that it's merely the strength of the thermal stratification. Thanks for explaining!
It also explains in part why toward the end of their lives, hot water heaters produce less hot water. After the sacrificial anode erodes away, the galvanic corrosion attacks the dip tube that carries the cold water to the bottom of the tank so in stead it cools the water at the top of the tank.
@@bcbock Dip tubes are plastic where I am. And if you've ever been scuba diving, it's really amazing to encounter a thermocline, where the water at your palm is 65F and the water at your fingertips is 40F.
@@bcbock That's mostly explained by the bottom element being used more often, and tending to fail long before the top element fails, so instead of it heating the bottom of the tank, the top element is the only one that turns on, and heats just the top of the tank. often you can drain the tank and replace that bottom element and solve the problem of the tank having less hot water in it.
Stupid thing is I KNOW the layers not mixing happens even in the oceans, yet it would've never occurred to me this also happens in water tanks with a higher temperature difference, or that this could be used to simply push hot water up with a cold water column....
The engineering of water heaters is fascinating- the MythBusters did some experiments with them and found that while they can fail, it takes some real effort to do so.
Yes, but when they do fail, it's spectacular - probably why the manufacturers make it so hard to actually make one fail. Stored energy is quite the thing.
@ccoder4953 absolutely! Even in nature, water is an incredible force. Put it under heat and pressure, and you got something amazing. Or terrifying. It really depends.
They’re a pressure vessel so there’s a lot of code around them and testing.
this makes a lot of sense, anything that can store 7kwh of energy in thermal form is 99% of the way to being a bomb, so of course they'd engineer it for safety
I've had two fail with catastrophic leaks in my lifetime.
This is hands down one of the best channels on UA-cam. You restore some of the wonder I felt as a child who liked to take things apart and figure out how they worked. I really appreciate the level of research and thought you put into each video.
This and Captain Dissolution are my favorite learning channels
I just installed a heat-pump water heater this past weekend and the change in energy usage is crazy (like 10-12kWh of power a day down to 2.5), and I have it sucking in and blowing out air to the same place. Not great for all areas (I'm in FL, so it helps cool my house down now, too), but wow I'm impressed. Just crazy that i did it and saw your newest video (which apparently I'm 3 weeks late to, lol)!
I am in upstate NY and have a heat pump hot water heater and it is great. It’s in our unfinished basement and we use it all year. It dehumidifies the basement and it cost much less than an electric hot water heater to operate. Free basement dehumidifier without the putting heat into the room makes sense even during our cold winter months.
Converting electricity into heat directly is 100% efficient. But if you move heat from one place to another, you can get more than 4x the heat from the same amount of energy (which is where 300%-400%-500% efficiency figures come from).
The air also gets dryed which is very convinent if you want to dry your laundry faster.
Why not installing a solar heater?
@@1Eagler After Ian hit last year, seeing all my neighbors with solar heaters on their roofs being yanked off, I'm keeping everything off of it if possible.
Beyond the amount of effort you put into your videos for 11 out of 12 months, I want to thank you for including captions in your videos. It really helps me out.
10 and a half months. 'No effort November' turned into 'don't check the calendar December', if you recall.
@@benholroyd5221 Sounds like you checked your calender...
Without captions, I wouldn't have known about the Scaldingly Smooth Jazz! 😊
Yes, and it's great that he goes to such effort to make the captions spot-on! the last blooper just cracked me up
One thing that could be changed here is sometimes his notes embedded into the video end up behind the captions, making the former impossible to read thus they need to be placed higher on the screen.
Idea: You might also want to properly insulate the hot water pipes coming from the boiler to the ceiling of this room. Reason being: Since I added insulation, I noticed that the water gets hot at the tap/shower sooner than before.
Yeah, and according to his FLIR footage, he needs to wrap a blanket around it or something. Too much energy loss. I wrapped blankets around mine.
@@speakersteve9586 Blankets 😆
I wrap a blanket around myself so I don't have to switch on my very inefficient heating.
@@igotes you should get an ever so slightly more efficient heated blanket. Living in an very old house converted to all electric in the Midwest and it's a life saver and money saver
@@LoFi_Punk ~ A heated mattress pad to go underneath will up the comfort. Since heat rises have it start under you.
As a woman who's a lifelong renter and has a father who perpetually sees me as being 16, your videos are invaluable to me, Mr. Connections. The look on my dad's face when I actually know things about household appliances is just golden!
As a woman who used to work in a hardware store, I love this!
@@WouldntULikeToKnow. oh my Lord i can't even imagine all the dudebro customers trying to talk down to you 🙄
“Mr. Connections” 😂 I love that!
@@WouldntULikeToKnow. what was that like?
@@firstnamelastname7708 "My name is Connections, Technology Connections."
Smart home idea: add some sort of temperature detector (or a few of them) to your water heater, and next to each shower add a display that indicates how much hot water is available, and potentially also estimate time until the water is hot and whether hot water is already in use somewhere else in the house.
sounds simple enough. till you're charged 5 grand. i imagine that is why such things don't exist.
if u have enough money to do this u can get a constant heater
@@KarldorisLambleyi doubt adding a few sensors would cost many grands in material cost nowadays.
@@schok51 me too. but i was discussing retail price, not wholesale price. if a large commercial endeavour can fuck the little guy over, they simply go in with no lube.
For the labor, cost, and complexity of the displays, temp sensors, flow sensors, wiring, and computer needed to make that work, it would make so much more sense to just get a large enough (or tankless) water heater and eliminate that concern.
The surpassingly sharp boundary between hot and cold water also happens in lakes. When the ice goes out in the spring the water mixes because it’s all roughly the same temperature, but once the top layer warms up the turnover stops. That’s why when you’re out swimming in a lake you’ll sometimes dive deep enough and notice a very abrupt change in temperature.
Even more incredible, it happens in the ocean, even though there are tides and currents. In fact, it is what allows currents - the oceans are basically one massive, looping conveyor belt (with smaller subsidiary loops as well) of water, driven by gravity.
The only time they gain or lose much heat is when in contact with the surface, and since polar air is cold, and cold water is dense, it sinks. As it travels around the world, it stays cold until it comes up to the surface. (This is why the deep ocean everywhere is just above freezing.)
That journey around the world? About 5000 years, if I recall correctly.
The lack of mixing also has a crazy side effect - you can map out where there is more deuterium and tritium, from aerial nuclear testing, and see exactly where the surface waters are going down, and how fast they do.
Thermocline !
@@plabptng9 deuterium is stable and not radioactive, so i'm curious how it would be detected without taking samples and running them through a lab.
even for tritium, the extremely weak beta decay would be impossible to detect from aerial nuclear testing
I've experienced this while scuba diving in a large lake. At around 20 feet the water dropped about 20 degrees from the warm(ish) water on top and the cold water underneath.
The largest waterfalls are, in fact. Underwater. An underwater lake of cold water at the edge of, say, the continental shelf drops cold water over that shelf and bam. Underwater waterfall.
Just don't try to say "underwater waterfall" too fast.
Your off-peak approach is a common setup here in Australia and works well using ripple control. The device that controls it picks up on ripples in the supply current that are injected into the grid. There is also a random delay in when the circuit turns on to avoid everyone’s water heaters turning on at the exact same time. I’ve always thought it was quite a clever system.
Yeah, I thought that was a universal thing. Can't imagine running my water heater during the day - that would be so expensive.
Same in France. Don't know about random delay, but my dad's house had the heater switched on automatically from the electrical board, which offered 3 positions for the heater instead of 2: always off/on during off-peak/always on.
@@Nereosis16 Where I live in the northeast US, we don't have variable electrical rates (yet), so it doesn't matter from a price standpoint when appliances run. Thus, we aren't equipped with any off-peak scheduling technology. The only people around here who would have anything like that will be folks who generate their own electricity (usually with rooftop solar panels) and wish to use their own power rather than interact with the grid, but even that level of adoption depends on reimbursement rates. In my immediate area, reimbursement is 1:1, so it literally doesn't make a difference to your electric bill.
We also run our water heaters a lot hotter than 50*C, usually around 70*C, and we have a tempering valve that automatically limits the water output temp to 55*C or so to help prevent scalding burns.
Here in Germany these water-heaters make no sense unless you have solar on the roof.
The standard is a flat rate for the whole day so the electric heaters without a container is cheaper.
These may be efficient but just heating directly is even more efficient.
There are variable rates but they generally are not worth it except for special setups like solar or for EVs
The day-rates are so high that you will be worse off with that plan unless you hardly use any energy during the day.
This channel is so damn awesome, showing the magic behind the conveniences we take for granted.
You mean water heaters in general, or his production bloopers? 8)
wait. this is NOT a home improvement channel??
@@cheater00 Nice!
Yeah one of my favorite channels of all time
In the UK we have a dual rate electricity supply in some houses with electric water heaters so water is heated at night with the cheaper rate, the second heating element is on the "always on" circuit and only activates if the tank runs out of hot water. This also applies to the electric storage heaters which essentially just heat up bricks at night which then radiate their heat back out during the day
Similar systems exists, that utilize excess solar energy to heat water or other materials.
Fun fact: I found out about how long it takes for the water to cool shortly after moving in to the apartment I'm in now. I found out the hard way that one of the "light switches" that didn't seem to do anything in the bathroom...is connected to the water heater. I took a shower the day after turning it off and it wasn't as hot as I'd like, but it was okay. It's when I prepared dinner that evening that I realized I was out of hot water and eventually figured out it was that light switch.
Who puts a waterheater on a switched circuit? Wat
@@demondoggy1825 Lot's of people. You can switch it off when you don't use it or travel, or if you also have a gas water heater but keep the electric as backup, or if you're the kind of person who is afraid that you might get an electric electric shock while showering or touching the pipe when there is a fault in the water heater ( very unlikely if you have a residual current breaker, which you should have anyways because otherwise you could get shocked by any household device not just a water heater ). So it's not a bad idea. But an unmarked light switch is probably not a great way of doing that.
@@demondoggy1825 Someone who wanted to save energy?
@@ffoska That's only going to be a problem if you're the US military and have KBR as a contractor.
The GFCI in my bedroom is wired to the garage circuit, and vice-versa. *That* took forever to figure out. Since the bathroom in question is literally on the opposite side of the house. That said, my water heater stays hot when I turn it off for a 2-week vacation, as in when I turn it back on the fire doesn't need to light. It didn't 'cool off' for you. You just used up the hot water.s
I would enjoy an episode about tankless water heaters. I've had two over the years and there are certainly advantages and disadvantages. But in a family with multiple people using a shower or bath, they really come in handy sometimes. Also, I'd love to hear about recirculators which i haven't used.
I'd certainly love to see video(s) about tankless water heaters, water heat boosters, and hot water recirculators.
I also request an episode on tankless and also curious about hybrid systems, I feel like hybrid is what I'd choose.
Tankless water heater are great when you have more than 3 adults in the house that work during the day. Fighting over shower temp/time with two teenagers almost made me go bald. When the old tank died it was a no brainer.
I recently built a house in California and wanted to go completely electric. Also, since water is scarce and expensive, and the house is a big long ranch, I wanted recirculating loops. Turns out I couldn’t have both. All the electric heat pump water heaters say the warranty is void if you have a loop. We were forces to go with gas tankless heaters.
@@JoeBorrello is water really *that* expensive there that you have to trade the little bit of extra water use off to having super inefficient recirc loops so you spend way more energy?
I’d have looked into having multiple water heaters spread throughout the house, since I would also assume your wet areas are mostly clustered.
One interesting part of the water heater that you didn't mention (because that isn't part of the story you were telling) is those things on the water pipes near the top of the tank. They are Dielectric insulated unions, which provide dielectric insulation between two dissimilar metals, which prevents galvanic corrosion. The tanks are usually steel, and the water pipes copper, so that insulation is needed between them.
I bet they're many times more expensive than a CPVC nipple, which would do the same job. And if CPVC isn't code in your area, there's also PEX , which is also way cheaper.
That would explain why the anodes aren't really meant to be replaced. As long as that insulation wasn't defeated by some ground or other connection there wouldn't normally ever be a need for it. But if a single connect could be made from the tank to any other part of the water circuit. But if the system has a ground tied to the tank through the power and it connects to any other conductive surface with a different chemical make up that the water makes contact with, then electrolysis would happen. The bimetal creates a current that erodes the metal. That's why those metal sandwich batteries called rvs have water tank anode problems. This gives me an idea for a new type of thermal battery. Thanks guys
@@tylerdurdin8069 Galvonic corrosion has nothing to do with the metal tank rusting. You will always need a sacrificial annode due to the oxygenated water continuously entering the steel tank (iron+oxygen=rust). If you read any water heater manual, they mention checking and replacing the annode rod every 6months or year). Nobody does it. I have never heard of anyone doing it. The rod may last 4-7 years, then the tank quickly fails within a year. Water heaters are disposable appliances and are not made to last.
Back to galvonic corrosion. The dissimilar metals are not an issue without an electrolyte. Distilled or dionized water will not have any corrosion effect. However water quality and mineral content varies throughout the world. Effects of galvonic corrosion happens right at the point where the 2 metals and the electrolye touch. i.e. a copper fitting to a steel pipe with non-pure water inside. The effect will create a small voltage (less than 0.5 volts)
@@ecaparts "Distilled or dionized water will not have any corrosion effect"
u wut. Distilled water is particularly MORE corrosive than regular water. Some types of corrosion may be less likely, but other types become much more likely.
@@ecaparts, this is interesting. My previous hot water heater failed when it was about 15 years old, precisely because the sacrificial rod was spent. (In fact, it sprung the leak at the top, where the rod went in. Whoever installed that tank apparently also didn't know about dielectric insulated unions, which meant the plumber who replaced the heater had quite the time breaking through all the corrosion at the water connections.) The tank I have now is going on 16 years old, and I've been very concerned about the condition of its anode rod. I think the main reason why nobody checks it is because there is no easy way to do that. The only way I know of is to remove the rod and visually inspect it, but many water heaters, including mine, are installed in locations where it would be impossible to remove the rod and put it back in. The work-around, I guess, is to simply replace the rod every few years, as was suggested in the video, but I'm not going to attempt that myself, as getting the right articulated replacement rod requires some knowledge about water heaters, and I wouldn't be surprised if plumbers use some sort of torque wrench to ensure it's tight enough to prevent leaking or loosening without stripping the threads, which probably aren't designed for many rod replacements. For what it's worth, when I drained and refilled my water heater last spring, I found surprisingly little rust and silt in the water I took out. So, hopefully, my water heater still has some life left in it, but I still intend to have the plumber in soon to check it out.
The amount of surprisingly useful things I've learned from this channel are amazing. Space heaters, water heaters, air conditioners... All things that I've used in home repairs. If you've got anything on basic electric clothes dryers and washers, I'm sure it'll come in handy for a lot of people too.
Here in France I have a 200 litre tank very similar to yours, but with a single 1800 watt 230 volt element mounted at the very bottom next to its one thermostat. It's on a timer from about midnight to 7am and has never left us short of hot water even with guests staying with us. They are common here and very efficient. Great video, as always. Thanks!
Your idea for cheaper electricity water heating has been in use for a while. My family has an off-peak water heater which just means it has more insulation and a bigger tank. We have a whole separate meter for the cheaper electricity at night. Thanks for the videos, I never realize some things are so simple but so smart.
Yeah, this is completely normal to me… I’ve never heard of any of these health concerns? Do our heaters have some other mechanism for dealing with it?
@@gormster Australian here. We've always had an off peak electric hot water heaters. Just a timer in the switchboard. Has been that way for long enough for me to not know when it started.
From the Queensland plumbing standard "In hot water storage systems for residential buildings, hot water must be heated to a minimum of 60°C to prevent the growth of bacteria such as Legionella.
The fitment of a temperature control device ensures that the hot water is delivered to taps at a maximum of 50°C"
@@Lazy_Tim Same here in the Czech Republic. If you use electricity for any application with substantial accumulation ability, you can arrange a special plan with the energy provider so that they can remotely switch these appliances based on the network load. You have a guaranteed total runtime per day based on the accumulation capacity and a significantly lower electricity price during the off-peak times. The advantage is that you don't have to time anything yourself, it's drived by a signal going through the power lines themselves.
From France. I Never heard of a hot water tank that is always heating water. Here the hot water tank is always connected to a relay, controlled by the electrical counter for night/day indication.
Here in the UK it is common practice to have the water heater energised during the night - for the exact reason you mentioned (ie the cost per kW is reduced) and providing you have a tank with sufficient capacity (and the water is heated to 60°c) it provides plenty of hot water for the entirety of at least the next day - so fear not - your experiment can be deemed a great success!
Indeed. Often there will be a boost switch which activates the top element only for a period of time - so if you did somehow drain the entire tank during the day and need a bit more hot water, no problem - just turn on the boost to get a bit more without needlessly heating the entire thing.
Indeed - but also commonly only a 3kW element, which I suppose doesn't matter as it has 7 hours to do its job.
Economy 7 overnight hot water heating works really well
Also common in Australia.
In fact, for Double Technology Connections points, Hot Water has its own separately metered circuit on a mechanical timer!
Commonly referred to as "J Tariff".
Is Economy 7/10 really that prevalent? I haven't actually seen it used anywhere.
I learned this last year when I got a new water heater. The plumbers who installed it accidentally configured it in "commercial mode" where it tried to activate both heating elements at once. I would get a bit of hot water, and then it would pop the circuit breaker and go cold. Thankfully, the installers came back and fixed it.
Thank you for educating me on how my hot water heater works! Though I’ve worked on mine a few times, I don’t know if I truly understood how it worked. If your heater stops working (as mine did one morning with guests visiting), it is surprisingly simple to diagnose and replace a bad element (an extremely common problem on older heaters) and now I understand why it was the bottom element that I replaced. …but, I also now know that my failure to replace the anode likely limited the lifespan of the new element that I installed. Remember, a plumber would likely charge a small fortune to replace the entire heater rather than suggest the anode and lower element for $20-40.
I have also always had and actively used a timer switch on my heater but didn’t know that I should have used it to avoid peak usage hours. I only ran it 6-hrs a day but little did I know that it should’ve been something like 4-hrs in the wee hours of the morning and 2-hrs mid-afternoon. Duly noted.
You might be interested in the slightly different approach to this system we take in the UK: For a start, our water heater tanks are usually made of copper rather than steel, so there is no need for a sacrificial anode to protect them. The inner surface gets coated with a layer of copper carbonate after a few years of use (this is the green layer you find on the inner surfaces of copper water pipes), which protects the metal from further oxidation. If you have copper pipes joined to a steel tank, with both metals exposed to the same body of water, then the steel itself becomes the sacrificial anode and corrodes at an accelerated rate. The zinc or magnesium anode prevents that, but if you have no steel in the system and all the metal exposed to water is copper, this is not needed.
Another minor difference: Instead of a dip tube running down inside the tank, we just have the water inlet pipe connected near the bottom of the tank. Makes manufacture easier, but accomplishes the same task of only admitting cold water at the bottom.
Instead of having a pair of heating elements with one at the middle and another near the top, we usually have just one element, rated at 3 kW (13 amps) since we generally have 240 volts available everywhere. The top of the tank is usually dome shaped rather than flat, so the hot water outflow pipe is connected at the apex of the dome, with the hole for the heating element slightly to one side of the outflow pipe. Due to the curvature of the dome, the element is oriented diagonally, so it can be the maximum length the dimensions of the tank allow while still reaching almost all the way to the bottom of the tank. Because every level of the tank has part of the same heating element in it, you only need one element to heat the entire tank, and convection currents take care of the mixing between hot and cold.
That’s really smart! I have a stainless steel tank (in US) that also doesn’t require a sacrificial anode, but everything else is typical US design (in/out flow, dual-element, etc).
@@modquad18 One thing I forgot to mention before - a steel tank requiring a sacrificial anode will produce hot water with elevated levels of dissolved zinc or possibly magnesium, since these are the metals used for the anode. This doesn't matter if you're using the hot water for washing or showering - but if you are using it for cooking, then it can give the water an odd taste. Both of these metals are essential minerals for humans, but consuming too much of them is probably not ideal.
Just in case anyone wants to do any maths, UK changed to 230V rms in 1994, though the electronics A-level hasn’t realised that yet either.
@@IwnBru Apparently the national grid hasn't realised that change either: If I measure the mains voltage coming from my house sockets with the AC volts setting on my multimeter, it clearly reads 240 volts. In fact where I am specifically it reads 242, so slightly higher.
Yes, I've tried this with several different meters, and they all give the same result, plus or minus 1 volt. So unless every multimeter artificially gives a reading 10 volts higher than the mains voltage actually is, I would say that it's still 240.
@@lloydevans2900 Voltage standards are regulated at substations, at inline voltage regulators along the distribution line, and sometimes using a tap setting on the service transformer, with the intent that every customer on the circuit will see the target voltage plus or minus N% at their service meter. Can't comment on the UK, but in the US, the base voltage is nominally 120V and the tolerance is plus or minus 5%, which means anything between 114-126V is reasonable and represents normal operation. I'm in a suburban neighborhood and usually see 119-123V at the outlets year-round, depending on how much load the neighbors are putting on the shared service transformer. But in areas with long lines and seasonal loads (e.g. large irrigation pumps), customers may see averages more in the 110-115V range and experience seasonal variations.
Can't state enough how valuable I consider your channel. Learning and knowing about your every day appliances and technology is super interesting and can actively help you making better decisions when buying or repairing things as well as helping out the environment.
We're in a new home, and lost power recently. This led to an interesting lesson.
We've never had a gas water heater, so I was a bit surprised to find it working just fine after hours without power.
I incorrectly assumed it must have some kind of small back-up battery, but just learned about the thermopile/thermocouple that uses the heat of the water to power the electronics.
Would love to see a video on those, and their potential applications.
The pilot light is what usually provides the thermal energy to the thermopile.
@@johncantwell8216 good to know! Thanks!
This is also how most gas fireplaces work now too. Absentmindedly flipping on the wall power switch that controls mine during a long power outage last winter, I was shocked to see it turn on like normal once I realized what just happened. The blower fan doesn't work of course but it heated the whole house just fine.
Heads up on your water tank temperature setting. You want to set it minimum 60C or 140F. It's standard setting when installing due to legionella thriving in water tanks. Also while on the legionella topic. If you go away for any extended periods of time and your domestic water is not cycling it's a good idea to run all your taps when you get home and get all that possibly infested water out and fresh stuff in.
I cannot believe how good your videos are. They're just so incredibly topical. You break down everything you cover into chunks that are so understandable. It's really, really impressive.
One option to employ is a post-heater mixer. This allows you to have much hotter water in the tank without making it dangerous for people using it. This means that in a shower, you use much less hot water per second and can get more time out of the same size of tank. I've actually been looking at one of these because there is not actually much space between "not hot enough for safety" and "too hot for safety". With this, you can move the heater to heat "too hot for safety" but have the water coming from the hot tap be fine.
One consideration though, if the tank ever does leak or explode, you’re going to have extremely hot water blasting at you while you’re trying to get to the cutoff valve to stop the tank from refilling itself.
Even without a post-heater mixer I’m a fan of keeping water hotter (you can control the mix at the tap, but manually). Not recommended if you have kids or morons around.
@@thedave1771 Over-hot water is also dangerous for some elderly.
He actually mentions this at 20:00!
Post mixer is compulsory thing at least in most european countries, so you can easily put the thermostat anywhere from 65 to 90 C and still you get 55C from tap no matter what you do.
@@thedave1771 Almost never happens though. They more or less just fail by a leaking pressure relieve valve 99% of the time. The new heat pump water heaters use a post mixing valve built into the unit just fine. It helps as say 140F vs 120F is almost 50% more capacity of hot water. Maintaing the tank temp with a heat pump is very energy efficient so not a big deal, but their recovery per hour is very small so this helps them compete with natural gas or resistance heat units which have much higher recovery rates.
As a person who is effectively an intern for energy auditors, you have shed a great deal of light on topics I encounter in my every day, and that are important for people to know in general. I cannot thank you enough for this video and the many others you have made exploring how we use energy in our homes and the technologies these devices employ. You are truly a boon to any mind curious about their home, and about many devices besides. Thank you!
I have had my electric water heater on a timer for over 15 years. Never had an issue. Ran out of hot water a very small number of times. My old hot water tank lasted over 25 years using it like this for obviously most of its life. I did always wonder how the water always stayed hot all day. Thanks for the video.
As a chemical engineer grad now working in industry going on my fourth year, thank you for these vids. Mass and heat transfer is an incredibly beautiful subject and I’m really happy you’re showing it to so many people. The moment that weird and abstract equation that I thought I’d never use suddenly becomes a really amazing tool under my belt once I start asking myself how I’d go about about tackling the problems solved by this device you present. Like if I had to solve this problem, would I even be able to do it? How did they space the relays? How hard would the math be to model it vs. just iterating through a bunch of educated guesses? Is there some smart dude who figured it out beforehand so you don’t have to? Is that info behind a stupid paywall? Who the hell is Grashof and why do I want his number? Can I use this info to determine if my neighbor is trying to scam me into buying a crappy water heater or when mine breaks down? Haha seriously though, thanks! It’s refreshing, fun, and makes me love what I do that much more. Cheers mate
As one Chem-E to another, we just need to get this man into process control. Essentially, that what a smart home is: A set of simplified inputs and outputs, which are networked together to provide a central control system for common functionalities around one's house.
Love you thoughts! That's my real premise: Engineering is not a degree, it's a mindset.
I wish there were more people who are taking the heat that my refrigerator(s) give off, then aim that at my water heater. If I get a Heat Pump water heater, then take the cold air that comes from it and give it to the refrigerator. Take the heat from my clothes dryer and aim it at the water heater. That sort of thing.
I have a suggestion for a small change to your setup. If you change the load switch so instead of
turning off the power to the whole tank just connect the load switch to the bottom heater
(so the load switch breaks the connection between the top and bottom, so the top still overrules the bottom).
In this setup you will always have (some) hot water because the top element will always keep the top warm.
This can help in the odd case where you end up unexpectedly using hot water in the day.
I worked making load switches to control hot water tanks like this, and the electric company (who was installing
these in peoples houses for peek shifting) was worried about people running out hot water. We had a more complex
system where we monitored the tank temperature, but most of the time it worked out the same as just
disconnecting the bottom element.
I was going to say pretty much the same thing.
Many water heater timers have wiring for both elements (the fancy ones if have lockout timers for the top element.) It takes a bit more wiring knowledge, some extra wire, and you have to rewire the internals which isn't too difficult as you use the old wire to pull it. BUT the way he did it requires no knowledge of or extra wiring, so it's easy to try and remove when done. Also gets around code or permitting issues, or even renting.
There is already plenty of hot water left, so no need to heat it with on-peak power.
Here in the UK most people only run their water heaters at night, they all come with timers for that purpose. I have spent many hours in the bath wandering how they work so thanks for the vid :)
Yeah, I was going to come to say that, watching him talk about disease concerns. It's literally normal in parts of the UK, especially where there's no mains gas. There's usually a timer and a switch or button to turn it on to boost during the day if necessary.
The disease thing got me thinking, isn't that like the reason why you DON'T CONSUME the hot water? Even if there's no bacteria etc, it can still stay in the heater for days and almost become stale(idk if it's the right word) and have rust and stuff.
@@odkres Yeah remember that sacrificial anode? While it isn't toxic it still fills the water with metal ions over time, and it's generally more a "better safe than sorry" practice.
@@wjcferguson It's worth noting that we normally run our heaters hotter in the uk. 60C at the heater and 50C at the tap is considered the normal safe temperature. If water is routinely standing at 40C for several hours there's a significant risk of bacterial growth. That's why it's recommended to run your hot water through all your taps for a few minutes any time you've been away for a couple of weeks, it'll get back up to a temperature that'll kill most of those nasties off.
@@odkres I don't think we ever had issues with diseases in our water heaters and we used to live in a different house for 3 months in the summer. So 1 house had "mostly" stagnant water for 3 months and the other house for 9 months (eventually the summer house got a solar water heater).
But yeah, we'd never drink it.
My father was an electrician (among other things) and he didn't like it if the water heater was on while anyone was taking a bath. It's a common fear from that generation.
Occasionally on YT someone comes along and explains something in such a good way it makes you feel dumb for not already knowing it.. Love it..
Your expansion of my concept of what counts as a "battery" has been the biggest single change in how I view energy in all the time I've been alive.
A recurring theme in your videos is how subtle things can suddenly add up to something big and/or profound, if you just stop to think and stack them up in your mind for a moment, or if you see an application that isn't always obvious.
Thank you for your dedication to the fundamentals, stripping down devices to their component parts, and then building back up to an understanding of both *routine operation*, but also crucially, *unseen implications*. I will always cherish that special sauce element of your videos.
From one nerd to another, thanks!!!!!
Well, every machine is an energy conversion device. And as long as you are sufficiently flexible *when* the energy is being converted, you've got yourself a battery:
Solar-thermal power plant? Harvests energy from the sun and collects it as heat energy; and if you have a way to store that heat energy it can keep producing power through the night.
Electric car charger? Converts electric energy into chemical energy, and usually you have at least a 14 hour window inside of which you don't care when exactly it happens.
Washing machine? Converts electrical energy into clean clothes, and as long as you don't care when that conversion happens (you kind of do, because it's bad for the clothes to not go immediately into the dryer) you can store energy in the form of clean clothes.
Geothermal power plant? You could (probably) draw less hot water out of the ground to let the rocks heat to a higher temperature and then get more energy at peak times.
House cooling, Water boiler, ... as long as one can keep finding machines that consume, - I mean convert - significant amounts of energy and don't *need* to run at a specific time, there won't be an end to this list.
I love all of your videos. All the miscellaneous tech that we never think about, but are common in every day life. It's fascinating learning about it all and I feel smarter after each one.
Also, I really wanted to say that I love your subtitles. I know it's a lot of effort to put them in, and I just want you to know that it's very much appreciated.
Same here. It's so nice to be able to watch at night without waking up the little one.
In regards to energy storage, i can't recall if you've spoken on this before, but ice storage for large chiller installations might be an interesting topic. During the summers, make ice during the night, when energy is cheaper and offices and schools aren't occupied, then use that ice as a heatsink during the day.
My college has this. There's basically an olympic pool worth of water in a massive tank in the basement of the main building. It gets frozen at night when rates are cheaper and the ambient air is cooler making it more efficient. Throughout the day water is circulated through and pumped to the air handlers. A student designed the system in the late 60s for the then-new building.
There's a large facility in downtown Houston that does both district heating and, more importantly, heat sinking and chilled water for the rarer "district cooling". It opened around 1980 and has run ever since.
It's been done, but with the move to green energy, the time usage rates are going to go upside down. Cheap energy will be during the day when solar power available and night energy will be expensive as it will have to come from storage.
@@jblyon2 Remember A home size A/C with 3 tons capacity is equal to the cooling capacity of melting 3 tons of ice per hour.
@@hankkline7300 Yup, exactly. Assuming it was actually equivalent to an olympic pool (I do not know the exact capacity, it was just always referenced as such) that's 3750 tons of ice. For the 14 hours per day the AC was active, such a tank would provide roughly 268 tons/3.2 million BTU/hr for those 14 hours. That was just enough to cool the building on a moderate summer day given its size and energy saving features (very advanced for when it was built). There were 2 300 ton chillers on the roof to refreeze and provide additional daytime cooling when needed on hot days.
Solar PV Retailer (from Australia) here. If there is a Thermo-coupled Hot Water System in the house, I always strongly recommend a simple timer, which clicks in around 10.00AM and turn it off around 3.00PM. That way, it turns into an Energy Storage Device. Have done many, and there is no complaint of running out of Hot Water even for medium sized families.
Saves a lot of $$ on bills.
TC, you never fail to make any seemingly mundane topic interesting and fun. Plus your sense of humor is right in line with mine.
I look forward to every video you put out. Thank you man.
Yep, too bad they're few and far between, which makes them all the more precious!
Alec must walk his appliances as a farmer walks down the isle in his chicken coup. "So, who of you will be my breakfast today? You? You? Any volunteers? No?"
I’ve had the (mis)fortune of owning three different heat pump water heaters over the last six years. Finally found one that is actually great and I keep meaning to make a video here on my channel about the whole experience. This video is giving me the motivation to actually get to filming.
You should too many videos out there about how they're such a great thing to have, I was considering getting one, but the move from gas to electric had me worried (especially when electricity prices here are well over 3x national average), I guess luckily for me the rebates didn't apply to me because I didn't already have an electric water heater, so I went with a tankless gas instead.
I live in Florida and wanted to install a heat-pump water heater. I wanted to put it in a ventilated lean-to utility shed on the back of my house but they said it wasn't supposed to be run outdoors. It was mean't to be in a basement or garage. I guess it would cause excessive condensation and rusting if it was running in normal outside air.
Wow, what happened to them?
I put an AO smith in last summer.
I don't get any condensate for many months of the year, so I'm hoping it lasts. I can imagine them dying in humid climates when the evaporator stays wet.
@@jp-ny2pd in the south I can see that happening. It needs to be in a dryer environment.
@@Mike__B at least when your power goes out you still have hot water
Fun fact: the name of the temperature gradient is the thermocline. The properties of the thermocline is important for many applications, one which was showcased in the video. Another important property is the warping of sound in the instance of sonar. While not impossible, it is very difficult to detect objects while using passive sonar through a thermocline.
Your delivery is goofy, which is one of the reasons I keep checking in with you, I like goofy. AND, you provoke thought on some very interesting topics. Thanks, and keep up the good work.
If you wire your timer to only switch off the lower element, you get the best of both worlds. The upper half will still be reheated if you use more than half the tank, allowing you to draw more hot water than a single filling and ensure the water you get has been heated to safe levels. You then probably want to set the temperature for the upper element a bit lower to avoid it coming on during the day for a small general temperature drop.
My own water heater has been a pain in the neck recently - this video was just what I needed to get a better grasp on the situation. I've always wondered what's going on in a water heater. Now I know.
Great video as always!
Sounds like it would be worth hooking up only the bottom heater to the timer, or somehow setting up the top thermostat to trip an override on the timer. That way you'd normally only heat the cylinder overnight, but if you had abnormally heavy use you'd still get it heating back up again during the day.
Here's a tip for anyone sharing a home with 4 or more people. Crank the hot water temp to the maximum. It does make the water dangerously hot, but you will never run out of hot water. Instead of a shower being like 50/50 hot to cold water, it's like 20/80 hot to cold. A smaller volume of hot water is needed for someone to shower.
Yeah sure you can do that but, tank lifespan?
@@peterweatherley7669 Why would it shorten the tank life?
But then isn't the unit running more to keep the temp up? More electricity?
When I lived in the UK and now in Australia the water is heated by off peak electricity over night, and most days we have hot water all day. Our current heater uses a thermostatic mixing valve as you mentioned. In the UK the tank was smaller but had a boost switch for when ran out of hot water, this does not seem to be a thing on most heaters in Australia, so when you run out, you have no more hot water that day, which I find annoying, though that does not happen that often.
I've got one, but I don't use off-peak power. It's a necessity for solar-thermal when you get a run of cloudy days. Still comes out a hell of a lot cheaper than off-peak, though. Getting the system took something like a third off the power bill, even in the middle of winter, when the boost gets the most use.
You should do one about the hybrid heat pump water heaters with a coefficient of power of 4+ and a yearly cost around $100
Yeah, I bought my house with a 50 gallon GE hybrid heat pump heater and the cost difference is pretty crazy. The EnergyGuide sticker estimates only 1830 kWh of yearly use.
Even better, geothermal heat pump water heaters/tanks!
@@DLJaspah Yours must be a big one, mine is only 850kWh for a 45gl hybrid. Although mine is very new and I was very aggressive at finding the best efficiency model on the market.
The sticker says $103 at 0.12¢ per kWh.
@@miavaughn2393
Guys guys, you don’t have enough perspective. Where does the warm water go after leaving the faucet/shower head? That’s right, it goes into the drain pipes. Since drain pipes carry warm water when you use the warm water, you could make a heat pump that instantly pulls heat from the lost water and puts it back into the incoming water. Add some batteries to those things that you could charge at night and you have a very cheap to operate device that loses no significant amounts of heat overall.
@@cezarcatalin1406 Nice! I feel like I'm just min/max-ing my house at this point, the cost and efficiency gains are just a side effect lol. I already want to redirect the condensation drip from the A/C to a tank to use for watering plants or something. Debatably drinkable since while it is condensation, it's also dripping from the dust-and-who-knows-what covered coils, but I certainly could use it for more than just keeping the drain wet. 😅 From the time the drain line broke and had to drain into a bucket for a few days, here in Texas in the summer that thing puts out *way* more water that I thought it would! I'm kind of curious how much water I could actually get from redirecting the intake of the off-grid van's A/C to pull from outside if I have excess power. Probably not very much, but would be worth looking into since with solar power, water would be the limiting factor for how long it could be remote...
This is the sort of extremely simple, but very clever, solution that I love. Thanks for sharing. It's really amazing how well such a simple thing as two hearing coils and filling from the bottom works
Fantastic video. I'm a construction technology instructor, and you just taught me a couple things, so thank you... seriously, thank you.
In Australia is quite common to have off peak water heating, where the water heater is only on during off peak hours, typically 1AM to 5AM, and this heats the water for the following day. As you found, it doesn’t cool down significantly, unless you use all the hot water.
The off peak electricity charges are way less than standard day rates
Also very common to have solar hot water, where it only heats during the middle of the day. You size them a bit bigger and even after a rainy couple of days (with basically no heating) you still have hot water.
@Graeme, What are your peak and off-peak rates per kWh?
How about a follow up on how a gas heater works? Or if it's basically the same one on the differences. One thing I like about our at least 20 year old gas heater is that because it has an actual pilot light when we lost power for a week in below freezing temps, we could still take hot showers!
Gas water heaters are completely different in that they have a heating plate that's heated by a gas burner at the bottom of the tank and a baffle rod in a flue that runs down the entire middle that works like a heat exchange that vents at the top, with a singe thermostat connected at the bottom of the tank that controls the gas flow to the burner. They're fairly efficient but I think they can run out of hot water faster under heavy use. They are indeed handy in power outages though, because nothing runs on electricity, and the igniter is usually piezoelectric. We used to have one in our old house that was there before we moved in and had been in for 15 years or more prior to us using it for least 5 more before replacing it. I'd still have one if we got natural gas in this area. If you keep the anode rod changed out and flush the tank every so often, they'll last for many years.
A third type is the water-heated water tank that is heated by the circulated water in a radiator based home heating system. Such a water tank has thermostatic valves instead of switches, while the separate home heating system keeps the circulating water at 70° to 80° C (160° to 175° F), which is then directed wherever heat is needed. That home heating system can in turn run on any heat source from piles of chopped wood to excess heat from a nearby nuclear power plant. Though so far I have only enjoyed intermediate solutions like bio fueled power plants and a coke fueled home system from the 1940s.
Gas > Electric
Not to mention that electric water heater elements (especially the lower) scale up and shed calcium into the bottom of the tank eventually the scale covers the lower element causing it to overheat and burn out, and seeing as how the lower element does the majority of the work(didn't know that part about only running one element) it is a major problem. And that little drain spigot doesn't do anything for removing the scale. From what I have seen a water heater will scale up long before the anode rod is used up.
More modern one's don't have a pilot light but can auto ignite on a standard alkaline battery which will last for years.
The tank target temperature of 50˚C made me do a double take. Here in Norway we usually run our tanks quite a bit hotter. The thermostat on the tank has a range of 70-95. If your tank temperature is under 70˚C you need additional measures to prevent legionella spread (e.g. increasing the temperature at regular intervals and flushing your pipes)
Our water heater automatically goes to 70 once a month for legionella prevention. Have it set at 30 for the rest of the time (to reduce cost).
We do something similar in the UK, with the tank usually heated to 50-65C, and the controller periodically runs a “legionella cycle”, which brings the temperature up for an hour or so. In reality, you are actually perfectly fine to keep water in the tank at 50 without the legionella cycle, as long as the water gets used. Legionella requires *both* a certain temperature range and stagnant water to multiply. If you go through your hot water regularly, you won’t have legionella problems.
@@RussGreeno is your water supply a well? My water temperature has been about 125f (51c) for over 40 years. My newer heater is 132 (55c)
at the tap. Plenty hot.
The US standards require a small amount of chlorine or a couple of other chemicals in city water systems.....
I don't know how yours and other countries treat city water.
My observation as well. Here in Finland we have our tanks 55˚C+ to prevent legionella, and nightly water heating is the norm. So even though the water temperature drops during the day, 55˚C should be enough to kil all legionella in a few hours at most. Now I think our water heater is dumb and only does what the thermostat tells it to do, so I think our water heater does not periodically heat to super hot by itself.
@@Aethid exactly the same. Heat pumps get less efficient the hotter you run them. Our heat pump brings the water up to 55°C nightly. Then weekly the legionella cycle runs and heats the tank to 65°C off peak. Most legionella bacteria will die in less than a couple of hours at 55°C, the 65°C just makes sure it's good and dead.
Thank you technology connections and thank you to his patrons for supporting him financially. I get a lot from his videos. Also to subscribers for having good taste. Thanks.
Here in Australia, when we had a new water heater installed, they offered to install a distribution board integrated hot water timer for no cost (it was a simple mechanical one, but if we wanted a smart home integrated one, it was not that much more (can’t remember what the price was, so I don’t want to speculate and be wildly out given the recent price increases here) we have ours set up to run during the day as we have a rooftop solar panel array, but it has made a big difference to our electricity bill.
I got a new house, finished construction December 2019 in Tasmania.
No timer.
It was a 3.6kw single element 250L tank. My brother in law is a plumber so I asked him to replace my 3.6kw element with a 1.8kw element.
My morning shower would trigger the element to run for about 40min when my solar was only generating about 1.5kw. So I was paying peak electricity prices for half my hot water. Now it's a smaller element, it runs twice as long but my solar mostly covers it now reducing my morning shower by about 50c/day.
This is very interesting. No, that’s not a strong enough word. This stuff is some of my most looked forward to content. Learning about the little engineering marvels in my life is the highlight of every month or so. Thank you for this. Your interests, particularly as of the past few years seem to perfectly match up what I’m curious about, and you do an amazing job explaining them in detail but at an understandable level. I need like a full show with you as host explaining all the household devices we don’t think about.
On the topic of water heaters, I’m glad your take is that tankless isn’t worthwhile in many situations. When I heard how many BTUs a tankless water heater burns and why they often need to be gas, I was pretty shocked. My household does tend to take long showers so I do run into cold water issues when shaving my legs or something, but all in all, a tank water heater is still ideal for my situation. Maybe just a slightly bigger one. And maybe a hot water recirc loop so I don’t have to wait a minute for hot water. And maybe a heat pump water heater to take advantage of that technology. Hope you cover some of those topics in future videos if you have a chance.
Edit: the water stratification aside was some of the most interesting thermodynamic physics I’d ever learned. I learned about the huge amount of heat water used in high school and even did the coffee cup calorimeter experiment at the time, but the numbers didn’t really make an impression on me. And also the sacrificial anode detail - I’d heard about those but hell if I knew how they actually preserved the life of the tank. Oh and I didn’t know they were so well insulated - I guess it makes sense that they should be but I always thought it wasn’t enough. Guess appliance makers have had decades to perfect these things into the cheap and effective things we don’t think about now.
Speaking of heat pump water heaters, it would be pretty damn cool to integrate them into other heat managing appliances. Seems like it could be a good heat dump for AC systems. Or maybe could even be used as a large reservoir of heat for heat pump heating (I tried to use fewer “heat”s) for those particularly cold nights or when solar power or time of use electricity would make sense. I could imagine storing heat in water could be a lot cheaper than storing it in batteries if you have solar and excess energy in daytime. Sadly I haven’t heard of any kind of integration on this level, but it should come to market at some point given the rising prevalence of solar equipped homes. I can’t imagine the actual connections would be difficult - just the management of heat transfer and thermostats and schedules might be tough with existing dumb electronic controls.
Maybe it wouldn’t be worth the complexity or cost, but something tells me storing excess energy during the day as hot water for use in nighttime heating and dumping AC waste heat into hot water would reduce energy and battery demands by enough to make it worth it. Someone correct me if I’m wrong.
Before this video and the one about using a well insulated home as a thermal battery, I’d never thought about the whole potential of heat storage, but when we have so many power hungry appliances dedicated to heating or cooling the air and water in our homes, it makes a lot of sense to think of heat storage as a viable method to reduce consumption.
Along the same lines, hot water heating is used in a lot of large residential and commercial buildings. Pushing hot air through large ducts all over the building can be challenging. It results in lots of heat losses and it's difficult to control the heating among the many zones. Adding a heat exchanger in each room with a local thermostat makes it easy to heat or cool the air just as it enters the room as desired. The water pipes are much smaller than air ducts, can carry much more thermal mass, and are easy to insulate to avoid waste.
Just like your hot tap water, you can use heaters, heat pumps, and tanks to heat/cool and store water for your home heating and cooling whenever it's cheapest/most efficient and use that whenever a room requires it. Heating in particular is great because you primarily need the heat at night when electricity rates are typically cheaper and don't need it nearly as much during the day. With solar water heaters, you can even charge up that heat reservoir during the day and use it up at night, rather than having to store that energy in batteries. Our oceans naturally do this, which is one reason why coastal areas tend to be more temperate with smaller day time temperature fluctuations. When it comes to using sun, wind, and other renewable sources of energy, we can take a lot of inspiration from nature, which has been perfecting its usage of these energy sources for millions of years.
The whole "heating water over night" thing is very common in Europe.
Here we set the water to be hot by 6am (or whatever time your power becomes more expensive) and have a lagging jacket over the tank to keep even more heat in.
If you have a big family that showers in the morning you might set the heater to come on again for an hour or so during the day to top off the hot water for the evening.
I was surprised to hear you talking about it as a new thing.
You even can get your heating switched on and off by the power company remotely.
That worked at least 40 Years ago. Take that smart grid
Most people have a controller where they can schedule on and off times for the whole week. And these are quickly being taken over by smart controllers that you can control from anywhere. Our Tado detects when I'm home and turns the heating off when I leave the house. And i can schedule in as many on/off cycles as I want for both the hot water and the central heating. I think this is very very standard in UK so I too was surprised at how he has had to set up a little box to control the electricity.
In the US, power is cheep especially when one take into account transmission costs. Most placed in the US more of our power bill goes to maintaining the grid then to generating the electricity. It is only in the last 10 years that there has been the economic incentive to meter by time of use, and it took installing new electrical meters to make it happen. Prior to 2012 there would have been no reason to do this at our house because electricity cost the same no matter the hour.
@@Fluxkompressor Yeah, I was about to say this. Here in Hungary it's called "tariff B", "switched power", or "nighttime power" by older people. It has quite a big price cut compared to the regular price, and it's for water heaters only AFAIK.
Bojler eladó.
@@Chris5685 In the UK it's called economy 7, for 7 hours of cheap electric. Usually used in conjunction with storage heaters.
Adding the pipe insulation and a water heater cover/blanket insulation thing would probably help even more in a situation like what you’ve described.
Every single time I end up this on your videos I am pleasantly reminded that you are one of my all time favourite UA-camrs. Informative, entertaining, relaxing, and fun. 11/10
Yeah I'm so glad I found this channel.
For relaxing time, make it Alec Tech Connections time.
You should do a follow up to compare any differences in the heating process with a gas heater. That world be interesting. Keep up the great content!
Gas heaters have one major advantage over electric heaters: they're cheap to run in the US (usually) because natural gas is a byproduct of oil extraction.
I was thinking that the whole time.
From what I've heard, besides the cost factor which is depending mostly on where you are & the current geopolitical situation(s), gas heaters can do "on demand" heating.
It's not verified facts though so feel free to tell me it's not true :p
@@thibauthanson7670 I'm just one person, but I can confirm that even just turning on the hot side of any faucet even for a few moments I can hear my jet engine... er I mean my gas water heater kick on for a couple minutes heh and it was just replaced within the last 2 years...
I'm excited for that video of home electrification. Watching your videos on heat pumps is what got me to push for my wife and I getting a heat pump a few months ago when we needed to replace our 20 year old furnace and its been great. Personally as someone who never was a big fan of setting up fancy on off schedules for furnaces I've enjoyed the fact that the company recommended that you just pick a temp and leave it there for the heat pump.
00:29 🛠 Conventional electric water heaters have two heating elements (upper and lower) with the same power rating, along with two thermostats, preventing them from running simultaneously to avoid overloading the electrical supply.
04:41 🌡 Cold water enters the tank from below, pushing hot water out the top due to differences in density, creating a sharp boundary between hot and cold water.
06:32 ⚡ The lower heating element kicks in when the cold/hot water boundary reaches it, heating the water as it flows into the tank.
08:52 🚿 The top heating element kicks in once the tepid water from the lower element reaches it, providing an extra boost to the water's temperature.
10:20💡 The "1st hour rating" of a water heater refers to the amount of cold water it can bring to target temperature in one hour, combining energy input and stored hot water.
14:06 🌪 Using only the top heating element allows for faster heating of the water at the top of the tank, extending the availability of truly hot water.
16:30 🔋 A well-insulated water heater effectively acts as a battery, retaining heat for extended periods when not in operation.
18:27 🌡 Hot and cold water inside the tank exhibit minimal mixing, allowing hot water to remain at the top for extended durations.
19:54 💡 Conventional tanked water heaters can play a significant role in energy management, especially when operated strategically during off-peak hours.
20:47 🚿 Tankless water heaters may not be the best choice in all situations due to their high power requirements and inability to store energyfor later use. They may be more suitable for homes with severe space constraints.
In Australia quite a few electric hot water services work like that. Only reheating at night. I remember at a previous house there was actually a button on the power meter that could force the heater to heat water, albeit at the higher electricity rate.
Just had to replace two this week. Your video comes perfectly on time 😄
One froze from the bottom (makes so much more sense now !) increasing the pressure to the point of not only popping the pressure valve but also cracking the top and spitting water everywhere on the not so conventional electrical connections... It was... majestic.
Here in Australia it is very common to have our hot water systems using off peak electricity, which generally turns on around midnight and is off during the day. We don not have a bypass switch. I live in a rental property where 5 single bedroom units are serviced by 2 parallel single element hot water systems each with a similar size to yours. Some of the units have 2 people, so 260 litres of off peak hot water provides for 7 people. The only time we ran out of hot water was when the element failed in one of the tanks.
Very similarly in my country in Eastern EU - a decade ago it was even outright called "night electricity", it is a bit more convoluted nowadays but the idea in essence is still the same - the switch is actually on the provider's(!) side (thus gaining an extra ability to do something with the extra supply), which gives 8 hours of electricity per day, 6 of those outside of peak hours, and the minimal switching time is at least 15 minutes. This system is on a separate circuit and is billed separately of course (cheaper than the always-on, on-demand circuit everyone is familiar with), and is widely used to power water heaters. This works exactly becase as Alec said, they are batteries - they don't need to be turned on immediately just because they dip below the usual values by a few Celsius degrees, as long as the thermal mass is large enough for the usage rate.
@@AkosJaccik yeah it's called controlled load in Australia. It's because the coal power plants cannot shut down and they have to maintain turbine speed so they can ramp up quickly next morning. Sometimes the power during night is sold at loss for the spot price.
I am from Europe, specifically from the Czech Republic (a country between Germany, Poland and Austria). What you do at home has been common here for about 60 years and practically everyone has it, with the exception of those who heat water with gas. The difference is that they do not control themselves when the water is heated, but the heating is turned on remotely by the electricity distributor. It is a condition for obtaining a more favorable tariff. The basic tariff reduced in this way provides 8 hours of cheaper electricity for about 2/3 of the price every day, which can be used for anything (not only for heating water). It is divided into two blocks, usually 3-5 hours in the afternoon and the rest at night. I'm not aware of legionella issues. It is recommended to set the boiler temperature to 80 degrees Celsius for a few hours at least once a month, but no one follows it. So your reasoning is correct - it works :)
I have installed a few tanks and replaced elements in them, never gave it much thought, but you gave me a little insight in why they are the way they are, and replacing the anode does really help with longevity
In Britain traditionally the water heater design is a bit different; both elements are connected to near the top of the heater; the 'long' element is traditionally used for Economy 7 off peak use and does the job of the lower heating element, and the top element is for topping up if the hot water may run out; there is often a 'boost' button that turns the top element on for one hour. Because heat pumps are much more efficient they are now used a lot more, but the temperatures are lower and consequently the tank needs to hold a lot more water. In many instances a traditional heating element is scheduled to turn on once a week to get the temperature of the whole tank above 60 degrees for protection against Legionella.
The 'boost' button is fascinating. Thank you for your comment. Makes perfect sense but I've not seen this before as my area is heated with gas.
This is great! I always knew about the top and bottom strategy but didn’t know about the “chase” effect. You should consider getting a tank blanket too which installs in minutes to boost the insulation.
This is brilliant stuff.
We previously had a hot water tank but I'm unsure about whether or not it had its own heating element, because we also had a gas boiler. As far as I understood, we had to turn on the boiler's hot water switch, which would run hot water up to the hot water storage tank (big insulated tank on the upstairs floor, no space for it downstairs) then gravity would bring that water back down to the taps downstairs. Any hot water left in the tank would slowly go cold over time.
We have 3 people in the house, and I don't think a water heater such as the one in your video could keep up with the demand. We also felt the extra water pumped up to the tank that was left unused was a waste of energy. There was the logistical issue of the piping necessary to take the water upstairs then back down. There was also the issue of the tank taking up a bunch of storage where we needed space for other things. Finally there was the issue of water pressure; hot water and, actually, cold water too (we had a cold water storage tank sitting above the hot water one) only had about two meters of gravitational potential energy, and while it was plenty to wash your hands with, it really sucked for showering.
So we switched to a combi boiler and stripped all the tanks and pipework out. Now we have mains water pressure pretty much on both taps (I _think_ hot water running through the boiler loses a little pressure.) Hot water takes about 10 seconds to travel through the boiler and to the furthest pipe (shower.) No more turning the boiler on and waiting 5 minutes before the tank had enough heat in it. Also we converted the tank room into a storage area. I think it was the best decision we could've made.
Real thanks for inclusion of the metric calculations to your video! This is really thoughtful to the people that live outside the USA
In France, the water heating during off peak power generation is standard since 3 or 4 decades. The national operator, EDF, send a signal in the power line to tell your water heater to switch on or off. You can use that to do things like charge an electric car too. Our power being mostly nuclear, it's not easily throttled.
The sacrificial anode blew my mind, great tip !
Yep, same here in Czechia, I was surprised in America you have to do it manually.
Australia too.
We recently upgraded our heating oil furnace to an air to water heat pump. That same heat pump also heats our water boiler now. It has no issue bringing it up to 50 degrees. Would be cool to see a video on those.
I had to change the heating elements several times over the years plus a thermostat. This video does a great job explaining how these water heaters operate. 👍
Stay well, Joe Z
This was fascinating. I've taken this thing sitting in the corner of my garage for granted my entire life. It sparked my interest in how gas water heaters operate. Always love the uploads, much love, take care.
I own the German Version, on 380 Volt in Amsterdam.
I did the same what he did, mine is parallel elements too, only a bit more complex on the electronics, second element is only used when needed.
It can produce 24/7 hot water...
Same tech, 120 Volt is not practical, you need a better grid, sorry.
We just installed a new heat pump-equipped water heater in my parents' house and I'm definitely getting one for myself when this tank I have goes. It uses like 1/4 the power! More pumping, more now!
Also, with your strategy of using the tank as a thermal battery, I found an accessory at my local big box home improvement store that is called a "hot water tank booster" - it allows you to run your water heater at max temp, and then diverts some cold water into the hot water output lines to bring it back to a more palatable temperature. This would allow you to stretch your hot water supply even longer in your situation!
The more usual name is "tempering valve"
Ah yes, good old thermostatic mixing valve :)
That's definitely interesting. You could set the tank to 90°C, mix it down to 60°C to keep your warm water supply at a steady temperature and to increase the tanks virtual capacity by 50%
I love my heat pump water heater.
I live in a cold climate and replaced an oil fired heater with it. No heat leakage through the flue pipe, this thing barely runs.
I have it in my basement which is cold, but I have a wood burning furnace that leaks hot air down there and I have noticed no difference in temperature this winter. I was afraid it wouldn't be able to keep up and would run a lot, but that wasn't the case.
If I powered it by solar I would install a tempering valve and set it to run during the day as often as possible, but my solar setup is off grid, running my chest freezer, refrigerator, and fishtank (It's tough keeping the snow away and getting sun in the winter)
Here in Australia it is a legal requirement whenever the hot water system is installed or serviced to fit a tempering valve.
The difference between 50 degree C and 60 degree water when it comes to burns/scalds is significant. Bonus that it makes your hit water system "bigger".
This was awesome, thank you. Years ago when I was in a large house, I added a 50-gallon very squat tank with absolutely no insulation whatsoever. And then I let the cold water fill that tank and just kind of sit there in the ambient air of the crawlspace, before it went into the actual water heater. This had a sizable impact on the energy used by the water heater. Of course that preheat was not entirely free, it was sucking heat out of the ambient air but it sure did make a difference.
Great job presenting the battery aspect of the water heater. I installed a 70-gallon natural gas water heater in my home when I built it 22 years ago. When the gas water heater died, I replaced it with an electric 50 gallon, 5500W, WiFi controlled water heater. I operate the water heater at 140 degrees during super off-peak times (10am - 3pm) when the cost of power is only 3.3-cents per kwh for 6 months (winter) and 5.2-cents per kwh for 6 months (Summer). I use a mixing value at the water heater to bring the temperature down a little so that it's not too hot at the faucets. My wife and I typically shower between 6am and 8am. There is ample supply of hot water the next morning for showers. It is more than 100' to the master shower, so I use a recirculating pump to move the hot water to the shower. The pump is connected to a smart outlet that is controlled by Alexa. I simply tell Alex, "Alex Hot Water" and the pump runs for 60 seconds. Since converting from gas to electric and using the tank as a battery, my gas bill dropped by an average of $50 per month. My electric water heater measures the power consumption so I can calculate exactly the cost. Last year I averaged $7.23 per month to run my water heater. That's $513.24 per year savings.
Here in the UK, in London, I switched from an old tank to a tankless heater. We are very severely contained when it comes to space, and the tank couldn't fill a bathtub. There might be bigger/better tanks, but for you to have an idea, it was likely half the size of the one in this video.
Yeah tankless is absolutely a necessary option for space constrained apartments. But some people are drooling over them as if they where a mew shiny thing that should replace all existing heaters... And that's just not the case for americans in detached homes.
I'm honestly tempted to go tankless in my house, there's bo baths just electric showers now so no need for the tank and gives us an extra 3m^2 in one of the bedrooms
We loved our tankless (gas) nearly endless hot water run 2 showers and run the washer
I use tankless because of legionella concerns, and the fact that many days we don't use more than like 2 gallons of hot water, while on other days we use tons of it.
People also don't maintain things the best, and I'm pretty sure tankless requires more maintenance/cleaning to be effective.
thanks for another great video man. myself having a background in electrical and hvac work I usually have a good idea of what you’re going to make videos like this about, but its the way you do it and the little details you add that always keeps it interesting and make me think in new ways. bravo sir
I just enjoy learning in depth info about how the mundane objects around my house work. I love these types of videos. You're always so thorough and I appreciate your work! great job Alec!
I love how you can take something so simple and make an hour long video about it. Your videos are not only entertaining but educational as well. Thanks!
In France, we have switches that know when the electricity is cheaper (my understanding is that the electrical company sends an electrical wave on the lines to activate the switch). These switches are commonly used to switch on and off the cumulative water heaters. There's really no issue whatsoever for diseases as long as there is power at least once a day.
I thought this was true everywhere. Maybe only in Europe?
@@Corloi it's true in Australia. You can hear the codes in the fan motor. There are different tariffs depending what you need
We have the same thing in the UK for "economy 7" homes. They turn on very late at night until the early hours of the morning when energy is a little cheaper - great for heating a tank of water, not so good for heating the rest of the home during waking hours.
never heard of such remotely controlled switches in Italy.
That's true. So long as the water gets over a certain temperature for long enough the legionella bacteria will be killed off. If you happen to have any coming in during the day the short time at a lower temperature isn't long enough for a colony to grow significantly. Any that is there will be killed off by the nightly cycle long before it can make you sick.
Thanks, a few comments. When I was younger and had teenagers taking long showers every day, I made modifications to my water heater to improve recovery time. Essentially, I doubled the power supply to the tank and made a few internal wiring changes so both elements could operate independently and simultaneously. Special care was taken to ensure that no portion of the wiring inside the tank was ever overloaded. The result, a quicker recovery time.
Today I am back to normal with a conventional electric water heater in our downsized empty nest. Now, I am participating in a pilot program from my local public utility. A controller has been placed on the power feed to the water heater. This allows the utility to turn off my water heater (along with other participants) at will remotely and minimize demand on the grid during times of high demand. Because of the tank storage, I am never short of hot water.
Finally, I employed a tankless water heater in a secondary home that was used mostly on weekends. This got rid of the standby losses from a conventional water heater when the house was unoccupied.
Letting the power company control your water heater sounds like a great idea until they or the government steps in and you can't turn it on even though you own it. People have already ran into this issue with the thermostat for their heating in times when people couldn't leave their homes due to snow.
@@GrandNebSmada Yup! They are doing the same thing with electric cars. Cars only make a small percentage of the world's Co2 emissions. It's got nothing to do with the environment and everything to do with control.
@@GrandNebSmada the wiring is in your house. You own it. Modify it to create a bypass switch for the water company's switch. No issue. If they really want control, they need to shut down all hardware stores. Call me when you see that happening.
The only reason I still have an electric tank in my house is because of the reduced rate offered by the power company for installing one of those relays.
@@GrandNebSmada what's better? they essentially turn down your thermostat to keep whole whole grid up, or have to start rolling blackouts to keep the grid up.. meaning NO electricity/hear for various periods?
FYI: You're losing more heat through the non-insulated hot/output pipe than through the whole whole tank. Because as you've said hot water rises (and copper is a great heat conductor). So if you want even better storage and hot water at the tap faster and efficiency then insulate your pipes! Plus you can measure the over-5h temperature drop after to verify how much of a difference it made, and more content for videos.
ever heard about legionella? hot tap water pipes may not be isolated. this creates the legionella bacteri to grow fast.
the boiler should be 60 celcius to prevent his. tip to prevent to much loss from the hot output pipe ! let it bend down direct at the boiler 1 foot al least the hot water will not go down and stays in the boiler. ps boiler means the tank !
Ok... this sat in my to watch list for quite a while, knowing it was going to be clever but unconvinced it was going to be sufficiently so. I finally got around to watching, and I am happy to say that this far exceeded my expectations. Thank you!