I have a prefabricated wooden house bult in 2005. 200m², underfloor heating downstairs, radiators upstairs. Equipped with a windhagen condensing boiler, 20 years old with weather compensation. I set a temperature of 21.5 degrees inside, and this week, -7 outside temperature, I ve been burning around 9m³ of gas per day...flow temperature @-7 outside is 40 deg. For both rads and underfloor. I follow all your videos. If it wasnt for you I would have never been able to understand and tune my system to get to this point. So a really big thank you for all the super informative videos you do. There should be more heating engineers as competent as you are around. Sadly there arent.
I recently began to watch your videos and I kinda feel that I need more. I'm addcited! And also fascinated with your work. These videos give me chills and make me want to learn about plumbing myself. I don't usually comment on UA-cam, but I liked it so much that I wanted to. Greetings from Spain!
Thank you so much for the hint. Lower temperature curve from 1.3 to 0.4 saved 40% gas in a day and 1 degree down in a house to 19C! I will try this experiment for longer. It might be best savings hint this year!!!
I watch all of you videos Szymon (as well as Heat Geek) and they are great - you are a real pro. Commenting because I'm currently using 180-210kwh/day gas in our 5 bed detached 1930's house (180m2). Worcester Greenstar 18ri running UFH downstairs and 8 rads upstairs with 55C flow, but house has uninsulated walls. I'm upgrading loft insulation plus upsizing rads from T11 to T21 (or T22) in prep for boiler swap or heat pump install, but currently can't keep the house warm on lower flow temps and Greenstar 18ri can't do weather compensation. Just a shame you don't cover Yorkshire otherwise I'd have you booked in ASAP. We need more knowledgeable and professional installers like you.
Thank you Szymon - As to watching your videos (and Heat Geek ones) in 18 mths I reduced my gas consumption from 17,000 kW to 8,000 kW per year. My current daily gas usage in this cold spell is ~50 kw so £3.50 a day. (previously it would be 100kW a day) This is with a 2009 Glow Worm Flexicom 24hx (10kW min turn down ratio of 2.4 and range rated to 15kW max) Property is an 80's 4 bed detached with normal improvements to insulation (DG, CW, 200 mm Loft insulation plus really good pipe insulation - thanks for the tips Szymon) heat loss of 4.5kW at - 2) All rads have been replaced with T22 (same size as original T11 rads) and I'm running a 48 deg flow temp with a 32 deg return so mean rad temp in mid 30's. Boiler cycles a lot...... It's going to be replaced with a Viessmann mainly for the improved modulation/turndown and weather compensation which I want - it's probably not going to save much more gas but it'll mean the house is more comfortable not matter what the weather does.
@@UrbanPlumbers - We've been in this house 32 years (Back in 1990 we were using 27,000 kW of gas a year) So heat pump - big problem is it's detached by a fag paper ;-) only place we could put a ASHP is in a narrow alleyway (think wheelie bin width max) with house wall on one side and 6ft close boarded fence on the other - worried about ending up with a heat pump being in it's own micro climate. Maybe 6ft in the air it might be OK but not many installers would do that so another gas boiler will see us thro to needing a care home rather than a house to live in
Efficiency is everything now. If only humans could be as efficient as machines. Consume less for oneself and give more to others. Keep up the good work on this efficient channel
Nice! 3 bed detached 2023 new build in Scotland, 85m2. 35kw gas combi boiler and type 11 rads. Flow temp 37 (hoping to get weather comp soon). Target of 20.5, setback of 19. We’ve been using between 25 and 35 kWh/day, so between £1.84 and £2.57 a day (excluding standing charge). But seeing this I’m tempted to set the flow temp even lower and increase the setback temp
Remember if you reduce flow temp and setback, it'll take much longer to get to your day time temperature on a cold morning (unless you have weather comp)
I have a full Tado setup on a Taxi 36KW Combi, weather compensated. It's nearly on the lowest setting, no flashy controls like yours, and will turn it down a bit more. We are about £70 a month during winter too. 95m2 £ bed semi. Northern Scotland but by the sea. very happy with the Tado radiator controls. Have 7 of them. Total instal price was £2200, no previous system. I did it myself!
I doubt it's weather comp, more like load compensation, it can't do modulation by speeding up or down the fan based on the inside and outside temperature.
@@derekclark7545from what I've read it uses an internet weather report as it's base for outside temperature in a specific location. It's not as accurate as an actual temperature sensor but it does a fair job with very little temperature fluctuation. Averaging around 60kwh per day heating, hot water and cooking. 4 bed detached about 80sqm
I've build myself a weather compensated system here with my wood burner. Works like a treat! Saves alot of energy, and I need to run the burner less often. (got 80kWh of thermal storage) Implemented it on a ESP running ESPhome, a 3-way mixing valve and 2 temp probes on the heating circuit. (one probe would be enough) Calculated with the known valiant heating curve. And with the known flow rate of the system I've even got a guess how much energy is currently needed to heat the house so I can plan when/how much to run the manual wood burner.
But the roof is currently not insulated, so i need to have a offset of 4° with a curve constant of 0.68, target temp 21°. Currently with -14° it's still working flawless with radiators only.
Here the Curve (you can plot it on the Desmos Graph Web Calculator for example) : y=R+N-M*(x-R)*(1.4347+0.021*(x-R)+0.0002479*(x-R)^2) y is the target water temperature for the heating circuit R is the target temperature for the room temperature N is the temperature offset M is the curve constant and x is the outside temperature (average the sensor data for at least 15min. valiant calls for a "low-pass filtering"; it's needed.)
Yesterday(9th) was £5.40 for us. 4 bed detached 114sqm. Greenstar 30 cdi boiler, I fitted weather compensation last year and changed most of the type 11 rads to type 21. house is set to 20 degrees from 0630 to 2230 and 17 degrees overnight. Think we are losing some efficiency with unbalanced radiators, no point sorting that now as a heat pump is going to be fitted this year. Heat loss on the property has been calculated at just over 7kw.
Waiting for the cavity wall insulation video! Your low consumption is also the result of a well insulated house I guess. My gas consumption was more than 210 kWh yesterday 😮
Have been waiting for your heat pump video as you said coming soon , looking forward to it , let’s hope it’s brilliant, I can’t see it not being so because all the others have been.
@@UrbanPlumbers With your videos it has given me an insight into the world of heat pumps which has generated interest in to this subject, Blown away with your knowledge but more than that , I think it’s your professional manner and the eye for detail, have been on this planet along time and seen many working trades but in my humble opinion not seen as good as you .
120 m^2 log house here in Finland, fully off grid. -27C outside, 24C inside. Wood gasification burner running the underfloor heating and a masonry fireplace, about 50 kg per day, harvested from my own land where I'm converting a tree farm into a natural, diverse forest. Processed the wood (cut and split) with electric tools in spring/summer with excess solar power. Cost: 0 Euro per day :)
@@Autonomegast About 5 years now, never going back. The independence, lack of monthly utility bills, the freedom it gives... it's a priceless feeling well worth the initial investment. Thanks for the sub!
Really impressive. What sort of insulation do you have? I have a Vaillant and looking to get the wc controls fitted so quite invested. Would love a longer / detailed video on the setup and control wiring etc.
Excellent video Syzmon.👍 You must have a very well insulated house. Mine - 5 bed detached (150M2) V200W all radiator system running weather comp on a 1.1 curve, - 2C target flow temp 43C running 24/7 (around 4.7 KWH) and maintaining a very comfortable 19C throughout the house (average of six independent thermometers)no set back so getting on for £10 per day. Insulation level poor but the killer I think is the double integral garage which is a bit of a heat sink.
80 ties build with insuated cavities and added internal wall insulation - 25mm PIR - so close to new build u vaule of walls and roof. Regular double glazing and uninsulated ground floor slab. Rads szied to 32C flow and UFH sized to 32c flow downstairs going in right now.
My setup is Vaillant turbotec plus combi boiler, 12 year old, 28 KW (non condensing), 8 rads (3 - 1200x400; 4 - 1400x600; 1 -1600x600), 22 type +1 towel rail, in a single series loop, controlled by Tado thermostat with all functions active, connected and configured for ebus protocol. I`ve got a detached 70`s old brick build, 125 m2, thick walls, 450-500mm, concrete floors covered with timber board, both uninsulated; loft has 200mm mineral wool insulation, except a room; double glazing doors and windows. I heat 24/7 at 22,7 C, no setback temp, no zoning, all TRV`s are fully open. I consumed 18 mc3/day, 10 EUR/8.6 GBP (10.01.), with an average outside temp of -3C throughout the full day. Tado modulates the flow of the boiler at somewhat low temperatures 42-52C, for the example above, (the boiler does cycle) and when it`s slightly warmer (0 to 5 C outside) between 38 -46C flow; on a sunny day 36-44C flow. Considering this operation mode do you think I could switch to a condensing boiler or save it for a major renovation I am planning in 2-3 years’ time (full insulation, underfloor heating, may be a heat pump)? Thank you and congratulations on your setup, something I aspire to. I`ve been watching your videos and Heat Geeks` for a while and I think you do a fantastic job on your projects, explaining the science behind it, sharing this information with everyone. Cheers from Romania
5 bed mid-terraced house built in 1850's with full wet UFH, Vaillant ecoTEC plus 637 boiler recently upgraded with Vaillant VR71 and weather compensation. Target room temperature set to 20C with set-back at 18C and heating curve 1.2, with current outside temp 1C the target flow temp is 47C but only achieving 41C and consuming around 200kWh or £15 per day of gas (including hot water and cooking).
Hello. Great video as always!! Im trying to figure out which type of system (underfloor or fancoil) will be best for heat and cooling in a new build running a heat pump. What is your opinion?
I'm on 100kwh, jan 9th, 2024 (£7.8) heating and hot water. 100m2 and 100year old semi. Roof 200mm and 100mm floor insulation. No wall insulation ish. Loads of windows in the house. Running 50C max on opentherm ideal logic max s30 with drayton wiser controls. Constantly cycling. Priority hot water system on s plan. Would drop the temperature to 30C but my boiler cycles a lot. Don't know if it's possible to make it not cycle? Or what else to do? Ideas? Without reinstalling new boiler s15 or smth like that. House temperature 20C, with setback at 19C at night.
Greenstar 30RI Compact boiler (newly fitted), heating and hot water (via a lagged hot water tank) for a 200m2 detached 1980 built house (pretty poor construction tbh) and in winter it costs us about £50 a week in gas - can't separate out the heating and hot water from the overall gas use as we also have a gas cooker. We recently upped the insulation in the loft, but we have areas of flat roof, old blown double glazing and questionable insulation in the timber frame walls. No weather comp, and a non-smart thermostat set to 19 during the day and 16 overnight. We run the boiler flow out at the recommended 2/3 of the way around the dial - there are no numbers given on it - to ensure it' condensing and the old fashioned thermostat doesn't seem to turn it on and off too much.
similar to me, 200m^2 victorian detached, but I turned my greenstar 18Ri into a weather compensated using a servo + 3d printed parts and microcontrollers monitoring flow temps….completely bonkers, but I am an electronics engineer….will be getting a veissman replacement soon, the modulation will be transformative
,Nice, can't wait for the next video, of your own heat pump install! we're in a rented flat, with E rated EPC and all electric (storage heater and radiative heater). Costs are £16/ day and it's not even warm (18 in the bedroom,
Yesterday was 96 kWh for me £6.80, 3 bed terrace, 1906 135m2. 200mm loft insulation, 100mm ground floor insulation under suspended wooden floor. Solid walls with no insulation. Ceiling height av 2.8m. Double glazed (about 25m2). I have an ideal vogue gen 2 system boiler, central heating set to 42dC. Was on for 16 hours. No weather comp but considering opentherm control upgrade this year. 300l unvented tank set to 55dC, heats for 1 hour per day 530-630am, doesn't run out with 2 people.
Ecotec pro VC 286 gas boiler, 130 m² floor circuit + 100 m² on 5 radiators on a single circuit. The floor circuit is connected as a radiator in // with its own circulator and 33° in max regulation. I am only a user in Belgium but I documented myself when we bought this well insulated house 4 years ago. everything was managed with a simple Honeywell ON/OFF thermostat... I added VRC700 and external probe in order to have modulation. And thanks to your videos explaining the flow rates, I finally managed to balance, without buffer the radiator circuit, the floor circuit as well as each of the 9 ground loops in order to obtain good return temperatures which are not too high for the boiler gas and which finally does not force it to stop, because with its minimum power of 9 kW, it does not modulate sufficiently low enough. the model chosen by the installer is too powerful. we heat the house to 21°C, at -5, the system works well with a curve at 0.55 unfortunately as soon as it goes back above 0°C the curve is too low so I have to raise it to 0.9 in order to avoid the cut-off, the floor return temperature is contained at 27°, the return mix with the radiators at around 30° towards the boiler. The next step will be the addition of an Arotherm plus 105 in order to make a hybrid system, a buffer, 2 circuits (radiator - floor) and perhaps a 3rd with a ducted convector upstairs for air conditioning in the summer with the floor. thank you for your very informative videos which will allow me to achieve this.
Well, I learned so much after 5 extra days waching you videos, it's amazing. BTW, today it's 8° outside and my boiler ran 4 hours et 37° straight this night without cut-off. (return at 30°) Also I did the heat loss calculation of my house : for 20° at -2 = 10 kW. I'm not considering the hybrid solution anymore, the buffer neither, and the 2 circuits neither too, even about the extra ducted convector for aircon only in the summer, An Arotherm Plus 105 400V will do the job perfectly. The house is made up of 3 phases in 400V because we have 2 electric vehicles, so I need a 3-phase heat pump in order to distribute over the phases. Sure a 75 could do it but it's MONO. I think I'll just add a diverter between the radiators (by default) and the convector (only in summer) in order to activate the cooling mode on both floor and convector in the summer.
I know you only posted the other day but weather is going really cold the next few days, wondering if you can post an uodate after the coldest day. Thanks.
I've got an Ideal heat Logic 24+ using Ideal's Halo controller. It's supposed to have Open Therm and geolocation weather compensation (set to 0.3) but the modulation control seems to only work when it feels like it. I'm only using it for heating. I have seen it controlling the flow to 38 degrees but not that often. It's usually too slow in cutting back, therefore, overshoots the thermostat setting and switches off. I have tried upping the thermostat and reducing the boiler flow temperature manually to 40ish but it doesn't seem to be able to control that low with the boiler cutting in and out over a couple of minutes. The boiler's minimum output is 4kw. I've a largish 4 bed detached with 12 largish rads. Comparing my gas usage to yours, I'm using about double. I'd be interested in your thoughts please. Cheers!
Great video, but I think we need a comparison. Can you turn weather comp off, set it at fixed 55 or 60c and see how much more it costs? My house is about 115 square meters with big rads up stairs and underfloor heating downstairs, i'm running at 55c and on a similar cold day I would expect to use 90-100kw (and i'd still be cold, usually set room temp to 17 or 18c). I do have quite big windows but reasonable insulation. Have tried running at 45 and was okay but I stepped down too much at night time and took too long to heat back up again, need to test properly with constant temp. Anyway, enjoy vids, thanks for info.
Last year before I installed weather comp and insulation it costed £10 a day on a cold day. After insulation but without weather comp it costed £5-6 a day. With bigger rads and weather comp it costs £2.5. Insulation and weather comp with bigger rads dropped the heating cost by 75%
@@UrbanPlumbers Ah, cool, thanks or extra info. I did see another video where mentioned insulation on your house, i don't recall all the details, perhaps you have quite a bit more than I do, not sure. I have a Baxi and keep meaning to add weather comp external sensor. Guess I need to try without my zones and leave it on a constant flow and see how low can run it.
That's a very interesting video, watched few of your previous ones too and it made me think about my new setup. Great job you are doing there, very informative channel. I'm actually in the process of installing UFH downstairs (open plan area with 55m2) so will have UFH zone downstairs and Rads zone upstairs. I'm running it at 50C flow but I think once I finish with insulation and airtightness, I should be able to go lower. I have a Nest with OpenTherm but was planning to go with Heamitser setup which will probably take me to a simple on/off per each zone. Now, I'm wondering if the OpenTherm path is worth keeping or not, considering I'm aiming to reduce flow temp & heat loss anyway. Multizone setup allows me for greater flexibility, however Heatmiser OT support is limited for multi zone setup hence simple on/off approach...unless I go expensive Honeywell. Anyone has any experience running OT on low flow temp and it's efficiency gain over traditional on/off multi zone setup?
that's seriously impressive, In the same weather I'm spending £10/day on gas alone albeit on a larger house. Sounds like I need to look at a modern boiler (current one is 17 years old and being serviced today) - so I should look out for weather compensation and modulation?
There is only 1 boiler worth looking at - Viessmann 200. But it needs to be installed by someone who understands weather compensation and system design
Looks like your Underfloor heating is @100mm pipe spacing. Well done for doing it the best way. 150/200 spacing is second class.Had an argument with Omni many years ago about pipe spacing and heat pumps, never used them since
Yesterday, just over £5 in gas (68.7 kWh) which includes cooking on gas to. 15 year old Valliant combi boiler with VRC400 with weather comp. 0.9 heat curve maintaining 19.5 C from 0600 until 2200 with a fall back to 18C over night. 109 m3 floor space to heat.
I went to weather compensation, and replumbing to a hot water priority, 1.5 years ago. Viessman 100 installed in a new build. House is 290 square m and 5 bed. (I’m skint) 2023 showed us using 9035kwh with setback temps 2c below day temps. Also have tado upstairs, and heatmiser downstairs (ufh) for geolocation etc. the Viessman is now the stumbling block as it won’t run on a low enough output from 5 degrees c outside temp and above.
One of the things that I most suffer from lowering my flow temperature is lack of radiators. I can pretty much run my boiler at 10% power output only on 60c flow temperature. Unfortunately it is a very small house with only 4 rads. I have it set to 40c flow temperature at night and 45 to 50c flow temperature during the day. That way the temperature varies from 19-20c inside while sleeping and between 20-21c while awake. That's the most efficient I can get with. All rads are fully open with manual valves. E.g. When the boiler fires up the flow temperature go from 30 to 40c in 5-10 seconds while flame is stabilizing and then it goes to 10% power output and it slowly decreases to 36c more or less and increasing slowly to 46c when it shuts off and the pumps keep running until it reaches 30c flow temperature and the process repeats again. Thats with flow temp set to 40c. The boiler is a Bosch Condens 2300i
@@kazan79 the valve that controls flow on the in side. The valve that is covered(out side) I have never touched and I suppose someone regulated it before I entered this home. And yes my boiler cycles a lot... The lower the temperature the more it cycles.
@@liquelt thanks for quick reply. absolutely make sense and my in valves are also fully open. Although I have 8rads some of them are very small and single so want to replace them after winter. I might be wrong but I think when boiler cycles a lot (which is also my problem) that is where energy is lost as each time it starts with big flame and then slows down.
I have this issue too. I'm not using weather comp, but just tried manually reducing the flow temperature. At 30 deg C, it'll only run for 10 seconds before cycling. I kept upping the flow temp to the point where it'll keep running and it's 55 deg C. Any lower than that and the boiler will cycle. This could be a flow issue, the pump is set to level 2, but if I turn it up to level 3 it's just too noisy (and I think it is drawing air in, as it's a vented system). I also think the boiler is far too big for the property. It's 30kW in a mid-sized 4 bed detached.
@@shm5547 that is right. It is a matter of thermodynamics. The hotter the water the more heat the radiators can output. The calculations should be what is the minimum power output for your boiler and at what flow temperature you have to put in for your rads to output that power.
Do you have oversize radiators already installed for the ASHP? Is the house very well insulated? Your standard of workmanship is excellent and you really care about the work that you do. It's a real pleasure to see it. However, assuming people have the money for the work. The chance of them finding a heating engineer of your calibre is slim but thing is they won't find out until a while after the engineer has left and the system is not up to the task. Most people will pay top dollar for mediocrity but will be completely unware until it's too late.
100sqm 1930s 3 bed semi. Vaillant ecotec pro combi full weather comp with sensocomfort and very poorly sized rads - about £3.50 a day when its cold. I don't use setbacks either because ive got fed up of explaining to the mrs why the heating comes on at night 😅. Ripping it all out soon and throwing in a Vitocal 150 heatpump...video also coming soon 😄
I'm in a 2 bedroom house; rented; social landlord. 64 square meters; probably quite well insulated. Before Covid I signed up for a long (4 years I think) fix at 2.9p/kwh and therefore we did not care about efficiency much. Heating bill was ~£60pcm in coldest months. Retrofitted Ideal Logic System 15 boiler. Y plan. System design is clearly DT50 with lower temp target upstairs. Stupidly placed mechanical (honeywell) thermostat which seems to have a 3-4c swing. Set to 20c downstairs hits 21-25c with flow temp at about 70. After the fix ran out and faced with a £200pcm gas bill estimate in worst months I started twizzling with the flow temperature manually. Every evening set it to 70c so that the morning hot water cycle would complete and the house would be boosted back up to a comfortable temperature after overnight (boiler too loud to run overnight due to that stupid pump) then in the day use the thermostat as a temperature limit rather than a target. Within a week or two I could keep the temperature at 21-22c without hitting the thermostat just by adjusting the flow temperature. Saving about 30-40% gas and having increased comfort if you forget about that ruddy loud pump. Worst gas bills are coming in at around £100-120 ish pcm. Flow temperature once I've turned it down around 45c I think. I wish we could have the system modified for weather comp + hot water priority 😞
Since last year I am using the SensoHome control + external sensor for weather Comp on a Ecotec plus 832, which is unfortunately a bit oversized for my property. I have now reduced the Heatcurve to 1.1 and reduced the difference of day and setback temp (it was struggling to reach temp in the living room if the difference was high). I am already approximately 15% lower in gas consumption with this set up compared to previous Nest thermostat. Not sure if I can push the efficiency much, but reducing the heat curve and the difference between day and set back temp potentially will improve the comfort.
I too have a glow worm energy and was thinking of changing it to hot water priority but not sure if it can be done without the valliant wiring center as I’m keen on getting low flow temps for heating with a weather comp sensor .
Nice video, crazy low flow temp, well done! Do you know if I can get weather compensation for a Worcester Greenstar 30 CDi and what would a diverter valve do? It seems to be a £100 part that can be added to the system.
Mini split air conditioner in small 80's terrace. Between 7.5kWh/day and 10kWh/day when it's around 1 to 5 degrees outside - 7th to 9th January. Average rate on agile octopus £0.19/kWh so up to £2/day for the heating part, not including hot water.
@@UrbanPlumbers Yeah there's no single best option for everyone. It's hard to measure the COP of Air-to-Air but if there were two consecutive days with similar temperature, maybe I could go back to direct electric heating for one day to estimate it?
Ive got weather comp on my Ideal Logic 18kw heat only on a Y plan. The kit only cost about £60 on ebay and it works well. I just have TRVs and a programmable stat and leep the background heat around 16.5-17c in the day and up it to 18.5c-19c in the evening. I dont use the steepest heat curve until it gets about -5c outside. We are on the mid curve setting right now. Its an 1855 house with stone walls so not the easiest to insulate.....but we try.
@@UrbanPlumbers I managed to run my flow temp at 40c last winter but this year I'm enabling weather comp on my ideal logic 47-348-57 which also allows for opentherm. I can't get wifi to the property but I can use a mobile hotspot, I am looking for the best thermostat to use, any ideas?
Fitted a vr940f with outdoor sensor and switched from 2 zone system to fully open circuit.. gas usage has dropped 20% according to my latest annual statement.. however i will need to change some single rads to doubles upstairs on the north facing rooms as they seem to struggle with the lower flow temperatures.
Last two days our "smart" meter says we're using 27 pence worth of gas, obviously that's not right! Reset being performed later today outside. Szymon for complicated health/ financial reasons I can't/won't be having a heat pump. Can you advise on the most efficient way of heating water only please? Three bed semi currently on gas ch, only two adults and a lurcher. Downstairs sink, washing machine, cold fill, upstairs shower and sink. Hope it's ok to ask questions like this, tia. Looking forward to seeing more of your set up.👍
So im assuming the boiler ramps up its temp to achieve hot water temperature then drops again for heating so heating and hot water cannot both be heating at the same time
Hello Simon, I am a plumbing and heating apprentice in the UK and would love to learn everything you know. What would be your advise to a young man like me ? What do I need to do in order to learn all this technical stuff? I know you have mentioned HeatGeek on certain videos, but is that all I would ever need?
Do you use a traditional vented cylinder for stored hot water? If so which one? I’m guessing you’ll be using a “fast recovery” model given the hot water priority boiler.
£2.86 a day for me. 90 sqm 3 bed timber framed terrace with good loft insulation double glazing, blinds and heat reflective curtains in Cambridgeshire. Intergas RF 36 Eco. No weather compo. 21.5°c daytime and 17.5°c at night. 55°c flow temp. 1213.16 kwh at £07,31 gives £88.69 for Dec 2023. This includes hot water, gas hob and oven used often. Summer usage with no heating is about 300kw/h per month. Making the heating about 1.2kw per hour or less. Pretty good?
Did you upgrade any insulation at the house? I see you've got some glass French doors there too.. £2.50/day is very impressive. Must be quite low heatloss
@@gpbeck I am more than aware of the units of energy and power and that is why I sought clarification, which I thank you for. I am somewhat similar in terms of flow temps - V200W big rads, 24/7 weather compensation, 5 bed detached leaky house of 150m2 consumed 115KWH yesterday average temp 1 to 1.5C yesterday so about 0.768KWH/m2 (which spookily enough is exactly the same as yours - ish).
@@normanboyes4983 calculated heat losses were 9kW Actual 5kW so I ended up with beefy radiators. Think house is pretty airtight and wet plastered with Carlite which is weak but feels like polystyrene weight wise. Suspect it has helped thermally. Also ceiling plaster board is foil backed. My curve is 1.3 no offset.
@@gpbeck Good information.👍 I think we have travelled the same road🤣. The calculated heat loss for my place was 11KW and I matched new radiators to room heat loss - a mixture of new ‘matched’ and redeployed ‘close enoughs’ plus a couple of undersized ones (unimportant small rooms). Now I have the V200 it is clear that my heat loss is not 11KW, but rather 5 to 6KW (I need more data over a longer run of sub zero temperatures to home in). But what I really need is better insulation now. (I am running on a 1.1 curve, 0 level and set point 18, no setback just run at 18 24/17 my house is comfortable. (I did increase the set point to 19 when we went sub zero for about 24 hours).
I have my first ASHP to install. Are you still using an umbrella scheme for the paperwork or doing it yourself? It is just such a minefield with it? I’m starting the job soon but still thinking of grants etc for the customer.
@@UrbanPlumbers I have been in touch with them. The seem to supply everything and you have to subcontract through them. I’ve not been a subcontractor for 25 years. I’ll give them a call later. 👍 good work on the Glowworm. I especially like the fact you had a VR71 hanging about 🤣🤣🤣
My Baxi Platinum will not run any lower than flow of 59 degrees. If I set it lower say 50 it keeps heating beyond 50 on turns itself off before the room stat has reached its target. What can I do to lower the flow temps? Bigger radiators? I’d love a new boiler but this one works perfectly.
@neo_265, you're in my boat. I have a 2007 40kwh Duotec, heating a 4 bed detached up North. Boiler oversized (IMHO) by installer. Microbore copper feeding undersized radiators, some upgraded from type 10s!! I've gagged the lockshields as far as possible (1/4 to 1/2 turn open) and set flow temp to achieve a 55c return. Boiler cycles many times per hour. Love the simplicity of the Duotec being easy to maintain and like you I'm reluctant to change. My current thinking is to calculate house heat loss and upsize radiators (types 21 / 22) accordingly using stelrad data and lower temp factor. I'm limited by pipework but still seem to get high temps at gagged rads which is a positive. I'd be interested in any ideas you have to upgrade but keep the Platinum.
@@UrbanPlumbers Dead right. I have a 2007 Duotec turned down to achieve 55c return and it cycles more than Sir Bradley Wiggins! Keep the vids coming, they're top class.
This Gas usage is amazing! If you don’t mind what is the calculated heat loss of the property? And is this controlled by external sensor with no room influence? I assume at this low Gas usage that the boiler would be cycling all day even at these lower external temps? Unless there is some sort of buffer maybe. And is this for context heating 24hrs a day with setback over night. Thanks in advance for your response.
Thanks, the heat loss at 3.5kw is at 21 design temp? And is the boiler just allowed to cycle all the time or have you got a solution for this on your system, thanks again.
@@UrbanPlumbersnope we logged it over summer to keep an idea on gas usage, it is costing 4.60 a day alone , and uses 30.5kwh to heat a 120 litre cylinder twice a day at this time of year didn’t look at thf heating cost yet but is using , that is in a two heat cycle, I forgot to mention that the property has a 22kwh heat loss . And is listed in summer cost was about 4.90 a day , and right now is 11.30 a day gas heating 5 hours approximate on manual , as well as heat for water usage, cylinder empties twice nightly at the moment due to 5 people showing
My Valiant Ecotec Sustain is running with a static flow temp of 35C keeping house at 20c, dropping to 17 overnight. Weather comp and smart trvs are my next planned upgrade. Im around £2.50 a day gas at the moment.
About time someone realized that Vaillant and Glowworms weather compensation is the nuts, A condensing boiler with underfloor heating no mixing valve or pump, the weather comp controls how hot the water is going into the UFH and low water temp rads, you set that in software. Its as cheap as chips to run. or you can use large rads or fanned rads, the Vaillant Glowworm system uses a probe in the cylinder to do hot water flat out (no heating it is hot water priority) so a duel coll unvented just adds to the fun, like less that £25.00 a month to heat a 250ltr vessel and that's four adults and two of them take half hour to wash there long hair (girls). What I want to know Szymon is how you got the Vaillant controls talking to the Glowworm boiler as Vaillant changed the Ebus code to stop that after everyone was using a £60 outside Glowworm radio sensor instead of the £200.00 Vaillant one when they where identical.
If you use the Migo it can go on line and find 3 local weather stations to get an average outside temp, or you can use the outside sensor and other controls Glowworm make for a more accurate outside temp. Here he has hacked the vaillant controler to use with the Glowworm boiler
I wonder if you think it is suitable to install underfloor heating directly onto an existing concrete floor? It would cost a lot to dig out and replace!
Quick unrelated comment, I’m running my intergas xclusive on weather comp my set back temperature is 18 at night but mostly running around 21 during the day, the only thing is I’d like to tweak the heating curve but intergas technical didn’t seem to know how to do it and kind of disregarded what I was getting at by trying to make me increase the heating output. I know you have a lot of intergas experience and was wondering if you could point me in the right direction. The house is fairly comfortable and we have a few older windows which is increasing my heat loss somewhat but I just want the radiators to be a few degrees warmer when it gets below 1’c. Even thinking of going on to load comp but want to try a complete winter with the weather comp first.
Email me from my website and I will send you a manual for weather comp on your boiler. You need to go into the settings with a code 020 not 015 - that will give you options not listed in the manual. It such a shame that Intergas UK don't understand the product they sell.
My mum has a valiant eco fit pure heat only boiler fitted last year and used 111.6 kwh in gas. It has no smart controls. Is there anything that can be done to make it run cheaper?
glow-worm system boiler 180m2 bungalow UFH through flow temp is at 35degC no weather comp or set back bedrooms set at 18.5degC rest of the house 21.5DegC using about 90kw's @ 1-2degs outside. you could knock best part of 40% off your gas cost by moving to octopus gas tracker
I've got an vaillant ecotec plus gas boiler (only 3 years old), house is well insulated with internal thermal board (75mm) and new double glazing. Using approx. 125kw per day at the moment in this cold weather, flow is set at 55c. House is approx. 320m2. Is that good or bad? Don't have a weather compensation unit, would this help?
£24.93 yesterday (heating and hot water) on a weather compensated pellet boiler running at around 47 degrees flow temperature at 1 - 2 degrees outside. 4 x 15kg bags of wood pellets at £6.23 per bag.
@@pumpkinhead456 I'm not yet sure if it's the size of the house or the efficiency (or lack of efficiency) of the pellet boiler. I'm playing around with different heating curves and nighttime setback temperatures to optimise as much as possible. You're right though - All things being equal, the cost of wood pellets isn't massively different to gas, with the added benefit that we don't have a daily standing charge for wood pellets.
That is amazingly cheap as i am currently spending almost £10 a day for a semi detached 100m2. I am not sure to understand how the weather compensation helps saving energy. My house is set at 20 and boiler heat system at around 55. I heat all as my wife works from home and hates being cold.
Looking at the prices of fast recovery cylinders, you could get a combi-boiler for that. Would it be an option to fit a combi-boiler just for the hot water and a heat only boiler to run at a low flow temperature for heating?
I've been wondering something similar. Is there a compromise for small households that don't want to install a big water cylinder and already have a combi. Could those households fit a heat pump for heating and increase the life of the combi by a lot by only using it for hot water. We don't use a lot of hot water in my home but we do have the heating on most of the day.
Why on Earth would you want to buy two boilers to do a job that one boiler can do much more efficiently. A modern system boiler with PDHW does not need a high recovery cylinder - a standard one is fine.
@@normanboyes4983 a few reasons: 1. the heating stays on when there's hot water demand 2. no risk of running out of hot water 3. no need to find space for a hot water cylinder 4. could be more efficient than having a thermal store (depending on usage pattern) The downsides are needing to get 2 boilers serviced annually. Plus, I'm not sure if the standard gas feed to a property could cope with the gas flow rate required when both boilers are on. Saying that, my parents house used to have two boilers. Not sure of the configuration, but I think one boiler did upstairs heating and the hot water, with the other doing the downstairs heating.
@@shm5547 It’s your house and it’s your money so you can do exactly what you want. But, you may wish to know that if you are running your heating long and slow the house is always comfortable and there is enough thermal inertia so that when the boiler switches over to hot water there is no discernible effect on the house temperature. If you do not want to find space for a cylinder then a storage combi (like the Viessman 111) could be a sweet spot for you. BTW I have never run out of hot water so I think you may be exaggerating the risk to convince yourself. Having an open mind and honestly examine options often leads to better decisions.😉
@@normanboyes4983 well indeed, I do have an open mind, that's why I'm asking this question! Personally for me, I had a like-for-like heat only boiler, new rads and new vented cylinder fitted a year ago. I did consider the options, but the risk of leaks in the pipes buried in the concrete floor put me off even moving to an unvented system (parents had real problems when they went unvented, loads of pinhole leaks kept popping up for years afterwards, plus they kept getting problems with rusting expansion vessels). If I had been re-doing the pipework, then I would have gone unvented. I struggled to find a plumber that knew anything about weather compensation, opentherm or PDHW. So unfortunately just had to keep the S-plan system for simplicity. Now things are settled with the heating system, I am thinking about a conversion to PDHW, with either weather compensation or opentherm control from the Nest thermostat. The weather comp. is the simplest route, as the boiler manufacturer do sell a kit. However, I am keen to see if it would work 3rd party opentherm with the Nest. This is a bit unknown, as it's not officially supported by the boiler manufacturer.
So you are really proving the point that people should focus on getting the house insulated and flow temps down on gas rather than spending thousands on a heat pump
Have a glow-worm boiler, it would be interesting to see the real graphs of the boiler flow and return temperatures together with pump operation, how much it has to cycle. yes, you can see 29C flow, but there is no "gas" icon, that means the boiler is cycling, interesting the boiler turns the pump off so cooling down takes a long time. The main problem with those boilers is minimum delivery, which is 7.5kW for my boiler with 5kW maximum house demand, with "fantastic work" by a plumber done to zone everything with microbore also. Anyway, main point, how ugly and user unfriendly the Vaillant controls are!!! My £40 DIY controls are much more flexible and better. It is absolutely astonishing at what length Vaillant group goes to prevent other ebus implementations to lock to their ugly proprietary controls. Why do you need "weather compensation"? Let me guess, because your controls absolutely rubbish. My thermometer tracks temperature inside rooms with delta 0.01C and sub 10s intervals, I can adjust the flow temperature just based on that and inertia of the system, I can see less demand based on more sun or more demand in a windy day. But heat geeks are keep pushing for those manufacture controls, who just sucks at everything that is not rectangular white box :-(
I did similar with mine, I took our out dated oil boiler out and fitted LPG Vaillant, same split system. Can't for the life of me understand you installing air source. £2.50 a day for your heating... what is the point of going to the bother or Air Source.
@@UrbanPlumbers not in winter 2kwh per 1kw solar on a sunny day 9 jan, Dec Avg 0.5 kwh per 1kw of solar dec i have 10kw system total kwh for the month 160
@@ecoterrorist1402I think he's referring to seasonal offsetting. Export as much as you can through the good months on a strong tariff like octopus flux to build up the credit to cover you through the winter on a decent import tariff like octopus tracker.
That's some black magic going on. An incredibly low temp flow rate from a regular boiler whose minimum is supposed to be just below 5kw. So the hack allows the boiler to operate well below it's factory minimum output, would be handy to see how that's wired up?
alpha cd25 dial set mid way setting 6 9th Jan 2.6 avg 118kwh Gas UFH flow 34 UFH return 28 160sqm home bungalow 1930 EPC A+ 108 points heating on 24/7 room temp 22 roll on planning so i can install a heat pump Heat pump load calculated for a Vaillant aroTHERM plus 7 The Outside Design Temperature for postcode NR7 is -2.4°C At the Outside Design Temperature and a Flow Temperature of 35 °C the output power of the heat pump is 8940 W. The heat loss from the building at the Outside Design Temperature is expected to be 6600 W. The total area of the building is 158.15 m2, giving an average heat loss of 42 W/m2.
@@UrbanPlumbers 3 bed detached 60s/ 70s home, Thinking I have a massive heat loss issue cold wind blowing through extension light switches and under bedroom doors.
I wonder what the minimum power of a heat pump is while it's operating. A quick search suggests that the Glow Worm has over 7kW minimum; quite poor. I think Viessmann boilers go down to maybe 3kW or lower for the min power specification. Of course I'm thinking in terms of avoiding on/off cycling here.
Heat pumps modulate down to around 20% of max capacity. Viessmann 200 modulates down to 1.9KW. There are some boilers that modulate down to 3KW. Low modulation is key even with a V200W mine will cycle when outside ambient is 10C or above. So if I had a boiler that modulated to 3KW it would be cycling at 6C and above, modulating at 4KW would by cycling at 3C and above and modulating at 7KW for my house would be cycling at -3C possibly colder.
@@UrbanPlumbersI remember you saying that most houses have no more than 6-10kwhr heat loss, so 1.5kw will give great turndown ratio and control. The days of blasting the system with too much power should be gone with good heat loss calculations. A thing lacking in the trade unfortunately.
Valiant 812 system boiler with wether compensation and full Valiant controls etc. UFH in new part downstairs and there is no way the curve can be set that low, needs to be at around 3.6 and then its want to run at 68 degrees. How on earth you’ve managed that is amazing, to me me it is anyway
@@UrbanPlumbers the UFH is via a manifold with a blending valve which i’ve always had set to 55 from memory. The boiler flow is 68 and this shows as the target flow temp from within the config on the wall controller. But I certainly think you’re correct when you say that the system is working as correctly as it should.
I think you have something weird going on with your system if it is truly on weather compensation an all rad (reasonably sized system on a reasonably well insulated house at - 2C should not need to be targeting above 45C.
@@normanboyes4983 Thanks Norman. What you say us the main reason we went for it, the promise of a nice warm house with the maximum efficiency. I personally think the installer didnt have a complete knowledge of what was being installed. Our problem is that theres no installers nearby who appear competent for hs to employ to setup and or see why its not performing.
@@SME_Ste It is not an uncommon experience unfortunately, heating engineers of Syzmon’s expertise are both busy and scarce. A common mistake is not to have hydraulic separation when running both UFH and Rads - but there are some other poo traps. What part of the country are you in?
Hi Szymon, great to see you back with a new video. Can I ask what controls you used on this set up? I am looking to install a new radiators system and an unvented cylinder to a property and was considering using a glow worm system boiler based on it being £300 cheaper than the Vaillant. I would be interested to know what controls items you would recommend I need to control rads/towel rail circuit/ and 200 litre unvented cylinder in the most energy efficient way. Hope you can help. John 👍
Impressively low consumption for a detached house. My 4 bed semi is at 30kWh *input*, at cop around 3.5 at the moment so well over 3x your consumption. Medium/poor insulation :-(
It appears you've forgotten about Viessmann 200 boilers which come with everything out of the box. Our customers are paying around £1.5 per day but they are also cheating by using Octopus Gas smart tariffs. Weather comp + unbeatable modulation + insulation = heat pump will struggle to beat it! Congrats on the house!
yep I have a veissmann 050w which was picked for weather compensation option - and decent modulation ratio. Unfortunately its still a combi boiler so even max modulation means it cycles more than it should, but its a good test for hopefully a future heat pump without too many other changes. I’m paying around the same but am on octopus tracker so only paying 4.5p/kwh which helps.
@@MrKlawUK The 050W isn't comparable the 200 (Much better peak modulation so no cycling, more efficient and has a more advanced type of weather compensation). The 050 is entry level.
All very impressive, but i'm curious what happens when the Hot water tank calls for heat in your setup? Surely flow temp has to rise to well over 60deg to efficiently heat the tank which would also send the same high temp around your rads (assuming room stat also calling for heat) , or have you some kind of temperature regulation / down mixing going on, or is it set up for hot water priority, which effectively pauses flow to rads until HW is satisfied and the VRC raises and lowers the temp accordingly? Asking because I'm racking my brain looking for the best solution for my ongoing house renovation to make a fairly large house more efficient than it was, spent a fortune on insulation and draught elimination measures so far as well as the building work. Ground floor zone is (or will be) 100% UFH (pipe in screed), Upper floor zone is all rads, so both zones would work well at this nice low flow temp without the hot/cold cycle of basic on-off which I hate. Yet i also have a 250L HW tank to consider which needs around 70 deg flow temp to get the hot water to around 60/65. Looking at a new Vailant boiler, and new decent tank with low standing loss (maybe Vailant), 2 Nest stats for zones, Vailant VRC Softcomfort control with weather comp.
It’s set up on hot water priority so it will only send weather compensation heating into the heating. When hot water is called for you will lose heating for a short amount of time of say 10-20 mins until the hot water cylinder is fully recharged to the set temperature. This is only beneficial with a fast recovery hot water cylinder otherwise you would start to get cold, waiting for the hot water to re generate
@@Anthony-dh3ty One of those Marmite things.... I have no complaints about our Nests, works flawless so far and no worse (or better) than other stats on the market but look much nicer in my humble opinion, they just work (and keep working) which is more than I can say for Hive from my direct experience. What lets our system down is the Vailant boiler itself (a 12 yr old Vailant Ecotec 628 system boiler) the firmware is garbage and widely complained about how it handles modulation under variable load, spends more time cycling in guard mode than anything. The magic sauce is the Vailant Softcomfort in charge of the boiler (and weather comp), doesn't matter which 'smart' or dumb stat you use then.
@@UrbanPlumbers So HW Priority ... thought so, thanks. Would love a video or explanation how you got the VRC and Ideal to play together, I prefer Ideal over Vailant boilers but would like the softcomfort control exactly like you have.
Economy 7 is only for electricity not gas I thought? £348 is That your direct debit amount, what's your actually usage based off of your bills/smart meter.
OK now show me the trick of finding an equivalent boiler that runs on heating oil. Our boiler is the original from when the house was built in 1999 and it definitely needs replacing by now.
Now this is not a hater comment. If you have your system running that well and that efficiently then why the heat pump. What do you aim to achieve. Your current system is paid for so to spend thousands on heat pump for what. As I said genuine curiosity not a hater comment. I am sure you have a good reason.
Heat pumps costs me £0 to install after the grant as I do all the work myself. It’s the system (rads, ufh) that costs money and it does need one done to be efficient regardless of the heat source. Once the heat pump is in place I can then remove gas, don’t pay standing charge and run the heat pump from cheaper tariff or PV - making it pretty much free to run - or even better making money from excess PV sold to the grid.
@@UrbanPlumbers I can’t see you heating the house and a cylinder of water for less than £2 a day I hope you can because it a big spend to do all that I’d would probably have duel fuel given a choice
I have a prefabricated wooden house bult in 2005. 200m², underfloor heating downstairs, radiators upstairs. Equipped with a windhagen condensing boiler, 20 years old with weather compensation. I set a temperature of 21.5 degrees inside, and this week, -7 outside temperature, I ve been burning around 9m³ of gas per day...flow temperature @-7 outside is 40 deg. For both rads and underfloor. I follow all your videos. If it wasnt for you I would have never been able to understand and tune my system to get to this point. So a really big thank you for all the super informative videos you do. There should be more heating engineers as competent as you are around. Sadly there arent.
Great! Thank you for watching.
I recently began to watch your videos and I kinda feel that I need more. I'm addcited! And also fascinated with your work. These videos give me chills and make me want to learn about plumbing myself. I don't usually comment on UA-cam, but I liked it so much that I wanted to. Greetings from Spain!
Thank you for watching and kind words
Thank you so much for the hint. Lower temperature curve from 1.3 to 0.4 saved 40% gas in a day and 1 degree down in a house to 19C! I will try this experiment for longer. It might be best savings hint this year!!!
I watch all of you videos Szymon (as well as Heat Geek) and they are great - you are a real pro.
Commenting because I'm currently using 180-210kwh/day gas in our 5 bed detached 1930's house (180m2). Worcester Greenstar 18ri running UFH downstairs and 8 rads upstairs with 55C flow, but house has uninsulated walls. I'm upgrading loft insulation plus upsizing rads from T11 to T21 (or T22) in prep for boiler swap or heat pump install, but currently can't keep the house warm on lower flow temps and Greenstar 18ri can't do weather compensation.
Just a shame you don't cover Yorkshire otherwise I'd have you booked in ASAP. We need more knowledgeable and professional installers like you.
Thank you Szymon - As to watching your videos (and Heat Geek ones) in 18 mths I reduced my gas consumption from 17,000 kW to 8,000 kW per year. My current daily gas usage in this cold spell is ~50 kw so £3.50 a day. (previously it would be 100kW a day)
This is with a 2009 Glow Worm Flexicom 24hx (10kW min turn down ratio of 2.4 and range rated to 15kW max)
Property is an 80's 4 bed detached with normal improvements to insulation (DG, CW, 200 mm Loft insulation plus really good pipe insulation - thanks for the tips Szymon) heat loss of 4.5kW at - 2)
All rads have been replaced with T22 (same size as original T11 rads) and I'm running a 48 deg flow temp with a 32 deg return so mean rad temp in mid 30's. Boiler cycles a lot......
It's going to be replaced with a Viessmann mainly for the improved modulation/turndown and weather compensation which I want - it's probably not going to save much more gas but it'll mean the house is more comfortable not matter what the weather does.
Great results. Viessmann are the best boilers on the market when it comes to pure efficiency and controls. Why not move to a heat pump?
@@UrbanPlumbers - We've been in this house 32 years (Back in 1990 we were using 27,000 kW of gas a year) So heat pump - big problem is it's detached by a fag paper ;-) only place we could put a ASHP is in a narrow alleyway (think wheelie bin width max) with house wall on one side and 6ft close boarded fence on the other - worried about ending up with a heat pump being in it's own micro climate. Maybe 6ft in the air it might be OK but not many installers would do that so another gas boiler will see us thro to needing a care home rather than a house to live in
Can't some heat pumps be exterior wall mounted? Or put in your garden (if you have one) and just run more insulated trunked pipes to the house
Efficiency is everything now. If only humans could be as efficient as machines. Consume less for oneself and give more to others. Keep up the good work on this efficient channel
Nice! 3 bed detached 2023 new build in Scotland, 85m2. 35kw gas combi boiler and type 11 rads. Flow temp 37 (hoping to get weather comp soon). Target of 20.5, setback of 19. We’ve been using between 25 and 35 kWh/day, so between £1.84 and £2.57 a day (excluding standing charge). But seeing this I’m tempted to set the flow temp even lower and increase the setback temp
Remember if you reduce flow temp and setback, it'll take much longer to get to your day time temperature on a cold morning (unless you have weather comp)
I have a full Tado setup on a Taxi 36KW Combi, weather compensated. It's nearly on the lowest setting, no flashy controls like yours, and will turn it down a bit more. We are about £70 a month during winter too. 95m2 £ bed semi. Northern Scotland but by the sea. very happy with the Tado radiator controls. Have 7 of them. Total instal price was £2200, no previous system. I did it myself!
Hello,
Do you use a separate weather sensor or Tado built in weather function? Thank you
I doubt it's weather comp, more like load compensation, it can't do modulation by speeding up or down the fan based on the inside and outside temperature.
@@derekclark7545from what I've read it uses an internet weather report as it's base for outside temperature in a specific location. It's not as accurate as an actual temperature sensor but it does a fair job with very little temperature fluctuation. Averaging around 60kwh per day heating, hot water and cooking. 4 bed detached about 80sqm
I've build myself a weather compensated system here with my wood burner. Works like a treat! Saves alot of energy, and I need to run the burner less often. (got 80kWh of thermal storage)
Implemented it on a ESP running ESPhome, a 3-way mixing valve and 2 temp probes on the heating circuit. (one probe would be enough) Calculated with the known valiant heating curve. And with the known flow rate of the system I've even got a guess how much energy is currently needed to heat the house so I can plan when/how much to run the manual wood burner.
But the roof is currently not insulated, so i need to have a offset of 4° with a curve constant of 0.68, target temp 21°. Currently with -14° it's still working flawless with radiators only.
Here the Curve (you can plot it on the Desmos Graph Web Calculator for example) :
y=R+N-M*(x-R)*(1.4347+0.021*(x-R)+0.0002479*(x-R)^2)
y is the target water temperature for the heating circuit
R is the target temperature for the room temperature
N is the temperature offset
M is the curve constant
and x is the outside temperature (average the sensor data for at least 15min. valiant calls for a "low-pass filtering"; it's needed.)
You have to do a video about how you get vaillant controls to work with glow worm boilers
Yesterday(9th) was £5.40 for us. 4 bed detached 114sqm. Greenstar 30 cdi boiler, I fitted weather compensation last year and changed most of the type 11 rads to type 21. house is set to 20 degrees from 0630 to 2230 and 17 degrees overnight. Think we are losing some efficiency with unbalanced radiators, no point sorting that now as a heat pump is going to be fitted this year. Heat loss on the property has been calculated at just over 7kw.
Waiting for the cavity wall insulation video! Your low consumption is also the result of a well insulated house I guess. My gas consumption was more than 210 kWh yesterday 😮
Have been waiting for your heat pump video as you said coming soon , looking forward to it , let’s hope it’s brilliant, I can’t see it not being so because all the others have been.
Heat pump is already installed, just waiting for screed company to do the flooring on Friday. Boiler will be removed next week.
@@UrbanPlumbers With your videos it has given me an insight into the world of heat pumps which has generated interest in to this subject, Blown away with your knowledge but more than that , I think it’s your professional manner and the eye for detail, have been on this planet along time and seen many working trades but in my humble opinion not seen as good as you .
120 m^2 log house here in Finland, fully off grid. -27C outside, 24C inside. Wood gasification burner running the underfloor heating and a masonry fireplace, about 50 kg per day, harvested from my own land where I'm converting a tree farm into a natural, diverse forest. Processed the wood (cut and split) with electric tools in spring/summer with excess solar power. Cost: 0 Euro per day :)
handy if your time is free and you have ~10-15 acres to sustain that 50kg a day
@@tarkadahl1985 "if your time is free" --> saves me from having to go to the gym ;)
@@upnorthandpersonal not everyone goes to the gym 😘
How long are u livi g off grid now? Would u go back to the grid again?
@@Autonomegast About 5 years now, never going back. The independence, lack of monthly utility bills, the freedom it gives... it's a priceless feeling well worth the initial investment. Thanks for the sub!
Really impressive. What sort of insulation do you have? I have a Vaillant and looking to get the wc controls fitted so quite invested. Would love a longer / detailed video on the setup and control wiring etc.
Cavity bids plus 25mm PIR internally - u value around 0.25-0.3
Excellent video Syzmon.👍 You must have a very well insulated house. Mine - 5 bed detached (150M2) V200W all radiator system running weather comp on a 1.1 curve, - 2C target flow temp 43C running 24/7 (around 4.7 KWH) and maintaining a very comfortable 19C throughout the house (average of six independent thermometers)no set back so getting on for £10 per day. Insulation level poor but the killer I think is the double integral garage which is a bit of a heat sink.
80 ties build with insuated cavities and added internal wall insulation - 25mm PIR - so close to new build u vaule of walls and roof. Regular double glazing and uninsulated ground floor slab. Rads szied to 32C flow and UFH sized to 32c flow downstairs going in right now.
@@UrbanPlumbers I would not have expected anything less from you.😉 How have you tackled the uninsulated slab prior to laying the UFH?
@normanboyes4983 I don’t mind uninsualted slab - it will be a giant heat store if it’s run continuously anyway
@@UrbanPlumbers What would be your to go ufh system for an uninsulated slab?
@@Anthony-dh3ty castellated panels (pro fix plus) with 100mm centers snail pattern pipework (16mm) and 25-30mm gypsum based screed.
My setup is Vaillant turbotec plus combi boiler, 12 year old, 28 KW (non condensing), 8 rads (3 - 1200x400; 4 - 1400x600; 1 -1600x600), 22 type +1 towel rail, in a single series loop, controlled by Tado thermostat with all functions active, connected and configured for ebus protocol.
I`ve got a detached 70`s old brick build, 125 m2, thick walls, 450-500mm, concrete floors covered with timber board, both uninsulated; loft has 200mm mineral wool insulation, except a room; double glazing doors and windows.
I heat 24/7 at 22,7 C, no setback temp, no zoning, all TRV`s are fully open. I consumed 18 mc3/day, 10 EUR/8.6 GBP (10.01.), with an average outside temp of -3C throughout the full day.
Tado modulates the flow of the boiler at somewhat low temperatures 42-52C, for the example above, (the boiler does cycle) and when it`s slightly warmer (0 to 5 C outside) between 38 -46C flow; on a sunny day 36-44C flow.
Considering this operation mode do you think I could switch to a condensing boiler or save it for a major renovation I am planning in 2-3 years’ time (full insulation, underfloor heating, may be a heat pump)?
Thank you and congratulations on your setup, something I aspire to. I`ve been watching your videos and Heat Geeks` for a while and I think you do a fantastic job on your projects, explaining the science behind it, sharing this information with everyone.
Cheers from Romania
5 bed mid-terraced house built in 1850's with full wet UFH, Vaillant ecoTEC plus 637 boiler recently upgraded with Vaillant VR71 and weather compensation. Target room temperature set to 20C with set-back at 18C and heating curve 1.2, with current outside temp 1C the target flow temp is 47C but only achieving 41C and consuming around 200kWh or £15 per day of gas (including hot water and cooking).
Hello. Great video as always!! Im trying to figure out which type of system (underfloor or fancoil) will be best for heat and cooling in a new build running a heat pump. What is your opinion?
I'm on 100kwh, jan 9th, 2024 (£7.8) heating and hot water. 100m2 and 100year old semi. Roof 200mm and 100mm floor insulation. No wall insulation ish. Loads of windows in the house. Running 50C max on opentherm ideal logic max s30 with drayton wiser controls. Constantly cycling. Priority hot water system on s plan. Would drop the temperature to 30C but my boiler cycles a lot. Don't know if it's possible to make it not cycle? Or what else to do? Ideas? Without reinstalling new boiler s15 or smth like that. House temperature 20C, with setback at 19C at night.
Greenstar 30RI Compact boiler (newly fitted), heating and hot water (via a lagged hot water tank) for a 200m2 detached 1980 built house (pretty poor construction tbh) and in winter it costs us about £50 a week in gas - can't separate out the heating and hot water from the overall gas use as we also have a gas cooker. We recently upped the insulation in the loft, but we have areas of flat roof, old blown double glazing and questionable insulation in the timber frame walls. No weather comp, and a non-smart thermostat set to 19 during the day and 16 overnight. We run the boiler flow out at the recommended 2/3 of the way around the dial - there are no numbers given on it - to ensure it' condensing and the old fashioned thermostat doesn't seem to turn it on and off too much.
similar to me, 200m^2 victorian detached, but I turned my greenstar 18Ri into a weather compensated using a servo + 3d printed parts and microcontrollers monitoring flow temps….completely bonkers, but I am an electronics engineer….will be getting a veissman replacement soon, the modulation will be transformative
,Nice, can't wait for the next video, of your own heat pump install!
we're in a rented flat, with E rated EPC and all electric (storage heater and radiative heater). Costs are £16/ day and it's not even warm (18 in the bedroom,
Yesterday was 96 kWh for me £6.80, 3 bed terrace, 1906 135m2. 200mm loft insulation, 100mm ground floor insulation under suspended wooden floor. Solid walls with no insulation. Ceiling height av 2.8m. Double glazed (about 25m2).
I have an ideal vogue gen 2 system boiler, central heating set to 42dC. Was on for 16 hours. No weather comp but considering opentherm control upgrade this year. 300l unvented tank set to 55dC, heats for 1 hour per day 530-630am, doesn't run out with 2 people.
Ecotec pro VC 286 gas boiler, 130 m² floor circuit + 100 m² on 5 radiators on a single circuit. The floor circuit is connected as a radiator in // with its own circulator and 33° in max regulation.
I am only a user in Belgium but I documented myself when we bought this well insulated house 4 years ago. everything was managed with a simple Honeywell ON/OFF thermostat... I added VRC700 and external probe in order to have modulation. And thanks to your videos explaining the flow rates, I finally managed to balance, without buffer the radiator circuit, the floor circuit as well as each of the 9 ground loops in order to obtain good return temperatures which are not too high for the boiler gas and which finally does not force it to stop, because with its minimum power of 9 kW, it does not modulate sufficiently low enough. the model chosen by the installer is too powerful. we heat the house to 21°C, at -5, the system works well with a curve at 0.55 unfortunately as soon as it goes back above 0°C the curve is too low so I have to raise it to 0.9 in order to avoid the cut-off, the floor return temperature is contained at 27°, the return mix with the radiators at around 30° towards the boiler.
The next step will be the addition of an Arotherm plus 105 in order to make a hybrid system, a buffer, 2 circuits (radiator - floor) and perhaps a 3rd with a ducted convector upstairs for air conditioning in the summer with the floor.
thank you for your very informative videos which will allow me to achieve this.
Well, I learned so much after 5 extra days waching you videos, it's amazing. BTW, today it's 8° outside and my boiler ran 4 hours et 37° straight this night without cut-off. (return at 30°) Also I did the heat loss calculation of my house : for 20° at -2 = 10 kW. I'm not considering the hybrid solution anymore, the buffer neither, and the 2 circuits neither too, even about the extra ducted convector for aircon only in the summer, An Arotherm Plus 105 400V will do the job perfectly. The house is made up of 3 phases in 400V because we have 2 electric vehicles, so I need a 3-phase heat pump in order to distribute over the phases. Sure a 75 could do it but it's MONO. I think I'll just add a diverter between the radiators (by default) and the convector (only in summer) in order to activate the cooling mode on both floor and convector in the summer.
I know you only posted the other day but weather is going really cold the next few days, wondering if you can post an uodate after the coldest day. Thanks.
I've got an Ideal heat Logic 24+ using Ideal's Halo controller. It's supposed to have Open Therm and geolocation weather compensation (set to 0.3) but the modulation control seems to only work when it feels like it. I'm only using it for heating. I have seen it controlling the flow to 38 degrees but not that often. It's usually too slow in cutting back, therefore, overshoots the thermostat setting and switches off. I have tried upping the thermostat and reducing the boiler flow temperature manually to 40ish but it doesn't seem to be able to control that low with the boiler cutting in and out over a couple of minutes. The boiler's minimum output is 4kw. I've a largish 4 bed detached with 12 largish rads. Comparing my gas usage to yours, I'm using about double. I'd be interested in your thoughts please. Cheers!
Great video, but I think we need a comparison. Can you turn weather comp off, set it at fixed 55 or 60c and see how much more it costs? My house is about 115 square meters with big rads up stairs and underfloor heating downstairs, i'm running at 55c and on a similar cold day I would expect to use 90-100kw (and i'd still be cold, usually set room temp to 17 or 18c). I do have quite big windows but reasonable insulation. Have tried running at 45 and was okay but I stepped down too much at night time and took too long to heat back up again, need to test properly with constant temp. Anyway, enjoy vids, thanks for info.
Last year before I installed weather comp and insulation it costed £10 a day on a cold day. After insulation but without weather comp it costed £5-6 a day. With bigger rads and weather comp it costs £2.5.
Insulation and weather comp with bigger rads dropped the heating cost by 75%
I may do a video about it as I have all energy data in a loop app
@@UrbanPlumbers Ah, cool, thanks or extra info. I did see another video where mentioned insulation on your house, i don't recall all the details, perhaps you have quite a bit more than I do, not sure. I have a Baxi and keep meaning to add weather comp external sensor. Guess I need to try without my zones and leave it on a constant flow and see how low can run it.
That's a very interesting video, watched few of your previous ones too and it made me think about my new setup. Great job you are doing there, very informative channel. I'm actually in the process of installing UFH downstairs (open plan area with 55m2) so will have UFH zone downstairs and Rads zone upstairs. I'm running it at 50C flow but I think once I finish with insulation and airtightness, I should be able to go lower. I have a Nest with OpenTherm but was planning to go with Heamitser setup which will probably take me to a simple on/off per each zone. Now, I'm wondering if the OpenTherm path is worth keeping or not, considering I'm aiming to reduce flow temp & heat loss anyway. Multizone setup allows me for greater flexibility, however Heatmiser OT support is limited for multi zone setup hence simple on/off approach...unless I go expensive Honeywell. Anyone has any experience running OT on low flow temp and it's efficiency gain over traditional on/off multi zone setup?
that's seriously impressive, In the same weather I'm spending £10/day on gas alone albeit on a larger house. Sounds like I need to look at a modern boiler (current one is 17 years old and being serviced today) - so I should look out for weather compensation and modulation?
There is only 1 boiler worth looking at - Viessmann 200. But it needs to be installed by someone who understands weather compensation and system design
It’s not just the boiler - you will likely need to upgun your radiators to achieve viable heating at such low temps.
Looks like your Underfloor heating is @100mm pipe spacing. Well done for doing it the best way. 150/200 spacing is second class.Had an argument with Omni many years ago about pipe spacing and heat pumps, never used them since
Yesterday, just over £5 in gas (68.7 kWh) which includes cooking on gas to. 15 year old Valliant combi boiler with VRC400 with weather comp. 0.9 heat curve maintaining 19.5 C from 0600 until 2200 with a fall back to 18C over night. 109 m3 floor space to heat.
That’s a decent result
Thanks. Liam @Custom Renewables is changing the system at the end of Jan for a Valliant arotherm and new rads.
Love your videos. Keep up the good work
I wanna know how you hacked vaillant controls to work with Glow worm!
I went to weather compensation, and replumbing to a hot water priority, 1.5 years ago. Viessman 100 installed in a new build. House is 290 square m and 5 bed. (I’m skint) 2023 showed us using 9035kwh with setback temps 2c below day temps. Also have tado upstairs, and heatmiser downstairs (ufh) for geolocation etc. the Viessman is now the stumbling block as it won’t run on a low enough output from 5 degrees c outside temp and above.
perhaps smarter viessmann thermostat with weather compensation could work
One of the things that I most suffer from lowering my flow temperature is lack of radiators. I can pretty much run my boiler at 10% power output only on 60c flow temperature.
Unfortunately it is a very small house with only 4 rads.
I have it set to 40c flow temperature at night and 45 to 50c flow temperature during the day. That way the temperature varies from 19-20c inside while sleeping and between 20-21c while awake.
That's the most efficient I can get with.
All rads are fully open with manual valves.
E.g. When the boiler fires up the flow temperature go from 30 to 40c in 5-10 seconds while flame is stabilizing and then it goes to 10% power output and it slowly decreases to 36c more or less and increasing slowly to 46c when it shuts off and the pumps keep running until it reaches 30c flow temperature and the process repeats again. Thats with flow temp set to 40c.
The boiler is a Bosch Condens 2300i
Do you mean that your rads are fully open on both sides (on in and out)? do you have a problem with Boiler cycling a lot?
@@kazan79 the valve that controls flow on the in side. The valve that is covered(out side) I have never touched and I suppose someone regulated it before I entered this home. And yes my boiler cycles a lot... The lower the temperature the more it cycles.
@@liquelt thanks for quick reply. absolutely make sense and my in valves are also fully open. Although I have 8rads some of them are very small and single so want to replace them after winter. I might be wrong but I think when boiler cycles a lot (which is also my problem) that is where energy is lost as each time it starts with big flame and then slows down.
I have this issue too. I'm not using weather comp, but just tried manually reducing the flow temperature. At 30 deg C, it'll only run for 10 seconds before cycling. I kept upping the flow temp to the point where it'll keep running and it's 55 deg C. Any lower than that and the boiler will cycle.
This could be a flow issue, the pump is set to level 2, but if I turn it up to level 3 it's just too noisy (and I think it is drawing air in, as it's a vented system). I also think the boiler is far too big for the property. It's 30kW in a mid-sized 4 bed detached.
@@shm5547 that is right. It is a matter of thermodynamics. The hotter the water the more heat the radiators can output. The calculations should be what is the minimum power output for your boiler and at what flow temperature you have to put in for your rads to output that power.
Do you have oversize radiators already installed for the ASHP? Is the house very well insulated? Your standard of workmanship is excellent and you really care about the work that you do. It's a real pleasure to see it. However, assuming people have the money for the work. The chance of them finding a heating engineer of your calibre is slim but thing is they won't find out until a while after the engineer has left and the system is not up to the task. Most people will pay top dollar for mediocrity but will be completely unware until it's too late.
yep - rads already in sized for the heat pump
100sqm 1930s 3 bed semi. Vaillant ecotec pro combi full weather comp with sensocomfort and very poorly sized rads - about £3.50 a day when its cold. I don't use setbacks either because ive got fed up of explaining to the mrs why the heating comes on at night 😅. Ripping it all out soon and throwing in a Vitocal 150 heatpump...video also coming soon 😄
Ohh I wish I went with 150 4kW and not Arotherm ! Will wait for your vid!
I'm in a 2 bedroom house; rented; social landlord. 64 square meters; probably quite well insulated. Before Covid I signed up for a long (4 years I think) fix at 2.9p/kwh and therefore we did not care about efficiency much. Heating bill was ~£60pcm in coldest months. Retrofitted Ideal Logic System 15 boiler. Y plan. System design is clearly DT50 with lower temp target upstairs. Stupidly placed mechanical (honeywell) thermostat which seems to have a 3-4c swing. Set to 20c downstairs hits 21-25c with flow temp at about 70. After the fix ran out and faced with a £200pcm gas bill estimate in worst months I started twizzling with the flow temperature manually. Every evening set it to 70c so that the morning hot water cycle would complete and the house would be boosted back up to a comfortable temperature after overnight (boiler too loud to run overnight due to that stupid pump) then in the day use the thermostat as a temperature limit rather than a target. Within a week or two I could keep the temperature at 21-22c without hitting the thermostat just by adjusting the flow temperature. Saving about 30-40% gas and having increased comfort if you forget about that ruddy loud pump. Worst gas bills are coming in at around £100-120 ish pcm. Flow temperature once I've turned it down around 45c I think. I wish we could have the system modified for weather comp + hot water priority 😞
Since last year I am using the SensoHome control + external sensor for weather Comp on a Ecotec plus 832, which is unfortunately a bit oversized for my property. I have now reduced the Heatcurve to 1.1 and reduced the difference of day and setback temp (it was struggling to reach temp in the living room if the difference was high).
I am already approximately 15% lower in gas consumption with this set up compared to previous Nest thermostat.
Not sure if I can push the efficiency much, but reducing the heat curve and the difference between day and set back temp potentially will improve the comfort.
I too have a glow worm energy and was thinking of changing it to hot water priority but not sure if it can be done without the valliant wiring center as I’m keen on getting low flow temps for heating with a weather comp sensor .
Nice video, crazy low flow temp, well done! Do you know if I can get weather compensation for a Worcester Greenstar 30 CDi and what would a diverter valve do? It seems to be a £100 part that can be added to the system.
You can, but is a boiler of the wall job I think
Mini split air conditioner in small 80's terrace. Between 7.5kWh/day and 10kWh/day when it's around 1 to 5 degrees outside - 7th to 9th January. Average rate on agile octopus £0.19/kWh so up to £2/day for the heating part, not including hot water.
It’s an option - I just prefer hydronics myself
@@UrbanPlumbers Yeah there's no single best option for everyone. It's hard to measure the COP of Air-to-Air but if there were two consecutive days with similar temperature, maybe I could go back to direct electric heating for one day to estimate it?
@@jibbilyYou can always use the degree days conversion.
Ive got weather comp on my Ideal Logic 18kw heat only on a Y plan. The kit only cost about £60 on ebay and it works well. I just have TRVs and a programmable stat and leep the background heat around 16.5-17c in the day and up it to 18.5c-19c in the evening. I dont use the steepest heat curve until it gets about -5c outside. We are on the mid curve setting right now. Its an 1855 house with stone walls so not the easiest to insulate.....but we try.
Thanks for your videos, I’ve learnt so much since watching them. What return temp are you getting or does it not matter so much with such a low flow?
at such a low flow I was getting around DT5 - so 24-25c return
@@UrbanPlumbers I managed to run my flow temp at 40c last winter but this year I'm enabling weather comp on my ideal logic 47-348-57 which also allows for opentherm. I can't get wifi to the property but I can use a mobile hotspot, I am looking for the best thermostat to use, any ideas?
Fitted a vr940f with outdoor sensor and switched from 2 zone system to fully open circuit.. gas usage has dropped 20% according to my latest annual statement.. however i will need to change some single rads to doubles upstairs on the north facing rooms as they seem to struggle with the lower flow temperatures.
Last two days our "smart" meter says we're using 27 pence worth of gas, obviously that's not right! Reset being performed later today outside.
Szymon for complicated health/ financial reasons I can't/won't be having a heat pump. Can you advise on the most efficient way of heating water only please? Three bed semi currently on gas ch, only two adults and a lurcher. Downstairs sink, washing machine, cold fill, upstairs shower and sink. Hope it's ok to ask questions like this, tia.
Looking forward to seeing more of your set up.👍
Do I need to buy the Vr71 or can I just connect the glow worm energy 18r with the valiant controller?
So im assuming the boiler ramps up its temp to achieve hot water temperature then drops again for heating so heating and hot water cannot both be heating at the same time
Hello Simon, I am a plumbing and heating apprentice in the UK and would love to learn everything you know. What would be your advise to a young man like me ? What do I need to do in order to learn all this technical stuff? I know you have mentioned HeatGeek on certain videos, but is that all I would ever need?
@urbanplumbers how did you get the vr71 to work with glow worm, really want to do it but not sure how the controls will talk
Do you use a traditional vented cylinder for stored hot water? If so which one? I’m guessing you’ll be using a “fast recovery” model given the hot water priority boiler.
£2.86 a day for me.
90 sqm 3 bed timber framed terrace with good loft insulation double glazing, blinds and heat reflective curtains in Cambridgeshire.
Intergas RF 36 Eco. No weather compo. 21.5°c daytime and 17.5°c at night. 55°c flow temp.
1213.16 kwh at £07,31 gives £88.69 for Dec 2023.
This includes hot water, gas hob and oven used often. Summer usage with no heating is about 300kw/h per month. Making the heating about 1.2kw per hour or less.
Pretty good?
Did you upgrade any insulation at the house? I see you've got some glass French doors there too.. £2.50/day is very impressive. Must be quite low heatloss
Yes, injected cavity walls and also a bit of internal wall insulation added
V200w 60s bungalow 125 sqm 60mm bead filled cavity. Yesterday 1deg outside flow temp 44 return 30 constant 4kW consumption. 20deg rooms no setback. All big rads.
Could you clarify is that 4KWH total consumption for the day?
No 4kW is a measure of energy, So 4kW constantly 96kWh in a day. On a cold day.
@@gpbeck I am more than aware of the units of energy and power and that is why I sought clarification, which I thank you for. I am somewhat similar in terms of flow temps - V200W big rads, 24/7 weather compensation, 5 bed detached leaky house of 150m2 consumed 115KWH yesterday average temp 1 to 1.5C yesterday so about 0.768KWH/m2 (which spookily enough is exactly the same as yours - ish).
@@normanboyes4983 calculated heat losses were 9kW Actual 5kW so I ended up with beefy radiators. Think house is pretty airtight and wet plastered with Carlite which is weak but feels like polystyrene weight wise. Suspect it has helped thermally. Also ceiling plaster board is foil backed. My curve is 1.3 no offset.
@@gpbeck Good information.👍 I think we have travelled the same road🤣. The calculated heat loss for my place was 11KW and I matched new radiators to room heat loss - a mixture of new ‘matched’ and redeployed ‘close enoughs’ plus a couple of undersized ones (unimportant small rooms). Now I have the V200 it is clear that my heat loss is not 11KW, but rather 5 to 6KW (I need more data over a longer run of sub zero temperatures to home in). But what I really need is better insulation now. (I am running on a 1.1 curve, 0 level and set point 18, no setback just run at 18 24/17 my house is comfortable. (I did increase the set point to 19 when we went sub zero for about 24 hours).
I have my first ASHP to install. Are you still using an umbrella scheme for the paperwork or doing it yourself? It is just such a minefield with it? I’m starting the job soon but still thinking of grants etc for the customer.
Still using the Vito Energy umbrella - great guys, give them a shout if you need an umbrella
@@UrbanPlumbers I have been in touch with them. The seem to supply everything and you have to subcontract through them. I’ve not been a subcontractor for 25 years. I’ll give them a call later. 👍 good work on the Glowworm. I especially like the fact you had a VR71 hanging about 🤣🤣🤣
Do you still install Heat Pumps under Heat Geeks umbrella also?
Great advert for Heatpumps! 😂😂
Yeah - f£&k heat pumps 🤣🤣🤣
Flexicom 15HX F22 Gravity fed Pump good 3 Port Good No Air or Blockages, Any Idea?
My Baxi Platinum will not run any lower than flow of 59 degrees. If I set it lower say 50 it keeps heating beyond 50 on turns itself off before the room stat has reached its target.
What can I do to lower the flow temps? Bigger radiators? I’d love a new boiler but this one works perfectly.
You need a correctly sized boiler will good modulation.I don’t think Baxi have any boilers with decent modulation.
@@UrbanPlumbers I think mine has a min output of 10kW but it’s still too much for my 130sqm home. It’s a 28kw combi so it’s needed for the hot water.
@neo_265, you're in my boat. I have a 2007 40kwh Duotec, heating a 4 bed detached up North. Boiler oversized (IMHO) by installer. Microbore copper feeding undersized radiators, some upgraded from type 10s!!
I've gagged the lockshields as far as possible (1/4 to 1/2 turn open) and set flow temp to achieve a 55c return. Boiler cycles many times per hour. Love the simplicity of the Duotec being easy to maintain and like you I'm reluctant to change. My current thinking is to calculate house heat loss and upsize radiators (types 21 / 22) accordingly using stelrad data and lower temp factor. I'm limited by pipework but still seem to get high temps at gagged rads which is a positive. I'd be interested in any ideas you have to upgrade but keep the Platinum.
@@UrbanPlumbers Dead right. I have a 2007 Duotec turned down to achieve 55c return and it cycles more than Sir Bradley Wiggins!
Keep the vids coming, they're top class.
This Gas usage is amazing! If you don’t mind what is the calculated heat loss of the property? And is this controlled by external sensor with no room influence? I assume at this low Gas usage that the boiler would be cycling all day even at these lower external temps? Unless there is some sort of buffer maybe. And is this for context heating 24hrs a day with setback over night.
Thanks in advance for your response.
Heat loss at the moment is around 3.5kW, heating 24/7 with set back and no room influence. External sensor and pure weather compensation.
Thanks, the heat loss at 3.5kw is at 21 design temp?
And is the boiler just allowed to cycle all the time or have you got a solution for this on your system, thanks again.
@@snowdon463 this is exactly what I would like to know about boiler cycling all the time and I can see many people with exactly same question/problem.
I'm using around 3-4 m3 a day and my heating is on constantly maintaining 19c at around 45c flow temp
Yeah, I went a bit over the top with my heating system spec. 32c max flow with -2 outside
@@UrbanPlumbers It feels as if using a Vaillant Arotherm Plus on your house is like driving a sports car in first gear 🤣
It will be very oversized, even 5kw unit. I kind of wish I went with Viessmann 4kw but let’s see how Arotherm performs first
My glow worm doesn’t turn on. The main switch is on but it doesn’t show up
Yesterday our current g rated cost 11.20 a day ouch .. we worked out the always on pilot lite cost 4.60 alone no wonder why we want to upgrade soon
Pilot light alone can’t cost £4.60 a day as it’s an equivalent to 4.5kWh per hour. Pilot light will cost you less than 20 pence a day.
@@UrbanPlumbersnope we logged it over summer to keep an idea on gas usage, it is costing 4.60 a day alone , and uses 30.5kwh to heat a 120 litre cylinder twice a day at this time of year didn’t look at thf heating cost yet but is using , that is in a two heat cycle, I forgot to mention that the property has a 22kwh heat loss . And is listed in summer cost was about 4.90 a day , and right now is 11.30 a day gas heating 5 hours approximate on manual , as well as heat for water usage, cylinder empties twice nightly at the moment due to 5 people showing
How does this set up heat the cylinder’s DHW if the target flow temperature is so low due to the weather compensator?
A schematic would be fantastic.
It’s called hot water priority set up. Regular Vr71 with vrc700 from Vaillant
My Valiant Ecotec Sustain is running with a static flow temp of 35C keeping house at 20c, dropping to 17 overnight. Weather comp and smart trvs are my next planned upgrade. Im around £2.50 a day gas at the moment.
Weather comp and smart trvs shouldn’t be mentioned in the same sentence
@@UrbanPlumbers are you not a fan of smart TRVs? Im curious now as you're a lot more knowledgeable than me on system design. 😊
About time someone realized that Vaillant and Glowworms weather compensation is the nuts, A condensing boiler with underfloor heating no mixing valve or pump, the weather comp controls how hot the water is going into the UFH and low water temp rads, you set that in software. Its as cheap as chips to run. or you can use large rads or fanned rads, the Vaillant Glowworm system uses a probe in the cylinder to do hot water flat out (no heating it is hot water priority) so a duel coll unvented just adds to the fun, like less that £25.00 a month to heat a 250ltr vessel and that's four adults and two of them take half hour to wash there long hair (girls).
What I want to know Szymon is how you got the Vaillant controls talking to the Glowworm boiler as Vaillant changed the Ebus code to stop that after everyone was using a £60 outside Glowworm radio sensor instead of the £200.00 Vaillant one when they where identical.
If you use the Migo it can go on line and find 3 local weather stations to get an average outside temp, or you can use the outside sensor and other controls Glowworm make for a more accurate outside temp. Here he has hacked the vaillant controler to use with the Glowworm boiler
How did he do that then ??
I wonder if you think it is suitable to install underfloor heating directly onto an existing concrete floor? It would cost a lot to dig out and replace!
Yes it is. That is exactly what I am doing in my own house. I insulated slab becomes one giant heat store.
do you still need a room stat with a weather compensator?
No, I don’t use one
Quick unrelated comment, I’m running my intergas xclusive on weather comp my set back temperature is 18 at night but mostly running around 21 during the day, the only thing is I’d like to tweak the heating curve but intergas technical didn’t seem to know how to do it and kind of disregarded what I was getting at by trying to make me increase the heating output.
I know you have a lot of intergas experience and was wondering if you could point me in the right direction.
The house is fairly comfortable and we have a few older windows which is increasing my heat loss somewhat but I just want the radiators to be a few degrees warmer when it gets below 1’c.
Even thinking of going on to load comp but want to try a complete winter with the weather comp first.
Email me from my website and I will send you a manual for weather comp on your boiler. You need to go into the settings with a code 020 not 015 - that will give you options not listed in the manual. It such a shame that Intergas UK don't understand the product they sell.
@@UrbanPlumbersthanks buddy you are a top banana
@@richard8303 email sent
Larger 4 bed house (1988) 9th Jan 118 kWh / £8.68 per day at 1C. Usage for 2023 for heating and hot water was 13,618 kWh and 2022 was 14,970 kWh
My mum has a valiant eco fit pure heat only boiler fitted last year and used 111.6 kwh in gas. It has no smart controls. Is there anything that can be done to make it run cheaper?
fit vaillant VR70 with VRC720 - it will make it miles better and cheaper to run
glow-worm system boiler 180m2 bungalow UFH through flow temp is at 35degC no weather comp or set back bedrooms set at 18.5degC rest of the house 21.5DegC using about 90kw's @ 1-2degs outside. you could knock best part of 40% off your gas cost by moving to octopus gas tracker
I am using 25kWh-30kWH a day. No need for gas anymore. The boiler is being removed today.
I've got an vaillant ecotec plus gas boiler (only 3 years old), house is well insulated with internal thermal board (75mm) and new double glazing. Using approx. 125kw per day at the moment in this cold weather, flow is set at 55c. House is approx. 320m2. Is that good or bad? Don't have a weather compensation unit, would this help?
not too bad for 320m2 house!!!
Great video as always. It’s a shame you’re so far away from me. I’d be more than happy for you to install a heat pump for me. 🙂
£24.93 yesterday (heating and hot water) on a weather compensated pellet boiler running at around 47 degrees flow temperature at 1 - 2 degrees outside. 4 x 15kg bags of wood pellets at £6.23 per bag.
Do you know what this is in KwHs?
@@pumpkinhead456 The ENPlusA1 standard demands at least 4,600 KWh/t. So 4 x 15kg bags of wood pellets would be around 276KWh.
@@forestandecho so quite comparable to a gas boiler! That must he a big house to require that amount of heat!
@@pumpkinhead456 I'm not yet sure if it's the size of the house or the efficiency (or lack of efficiency) of the pellet boiler. I'm playing around with different heating curves and nighttime setback temperatures to optimise as much as possible. You're right though - All things being equal, the cost of wood pellets isn't massively different to gas, with the added benefit that we don't have a daily standing charge for wood pellets.
That is amazingly cheap as i am currently spending almost £10 a day for a semi detached 100m2. I am not sure to understand how the weather compensation helps saving energy. My house is set at 20 and boiler heat system at around 55. I heat all as my wife works from home and hates being cold.
Looking at the prices of fast recovery cylinders, you could get a combi-boiler for that. Would it be an option to fit a combi-boiler just for the hot water and a heat only boiler to run at a low flow temperature for heating?
I've been wondering something similar. Is there a compromise for small households that don't want to install a big water cylinder and already have a combi. Could those households fit a heat pump for heating and increase the life of the combi by a lot by only using it for hot water. We don't use a lot of hot water in my home but we do have the heating on most of the day.
Why on Earth would you want to buy two boilers to do a job that one boiler can do much more efficiently. A modern system boiler with PDHW does not need a high recovery cylinder - a standard one is fine.
@@normanboyes4983 a few reasons:
1. the heating stays on when there's hot water demand
2. no risk of running out of hot water
3. no need to find space for a hot water cylinder
4. could be more efficient than having a thermal store (depending on usage pattern)
The downsides are needing to get 2 boilers serviced annually. Plus, I'm not sure if the standard gas feed to a property could cope with the gas flow rate required when both boilers are on. Saying that, my parents house used to have two boilers.
Not sure of the configuration, but I think one boiler did upstairs heating and the hot water, with the other doing the downstairs heating.
@@shm5547 It’s your house and it’s your money so you can do exactly what you want. But, you may wish to know that if you are running your heating long and slow the house is always comfortable and there is enough thermal inertia so that when the boiler switches over to hot water there is no discernible effect on the house temperature. If you do not want to find space for a cylinder then a storage combi (like the Viessman 111) could be a sweet spot for you. BTW I have never run out of hot water so I think you may be exaggerating the risk to convince yourself. Having an open mind and honestly examine options often leads to better decisions.😉
@@normanboyes4983 well indeed, I do have an open mind, that's why I'm asking this question!
Personally for me, I had a like-for-like heat only boiler, new rads and new vented cylinder fitted a year ago. I did consider the options, but the risk of leaks in the pipes buried in the concrete floor put me off even moving to an unvented system (parents had real problems when they went unvented, loads of pinhole leaks kept popping up for years afterwards, plus they kept getting problems with rusting expansion vessels). If I had been re-doing the pipework, then I would have gone unvented.
I struggled to find a plumber that knew anything about weather compensation, opentherm or PDHW. So unfortunately just had to keep the S-plan system for simplicity.
Now things are settled with the heating system, I am thinking about a conversion to PDHW, with either weather compensation or opentherm control from the Nest thermostat. The weather comp. is the simplest route, as the boiler manufacturer do sell a kit. However, I am keen to see if it would work 3rd party opentherm with the Nest. This is a bit unknown, as it's not officially supported by the boiler manufacturer.
Does you system run 24 hours, if not then surely your water temp is too low to heat a cold house
Not with the correct size emitters.
So you are really proving the point that people should focus on getting the house insulated and flow temps down on gas rather than spending thousands on a heat pump
My heat pump will be 30-40% cheaper to run than this boiler
I am after best efficiency regardless of your heat source
Have a glow-worm boiler, it would be interesting to see the real graphs of the boiler flow and return temperatures together with pump operation, how much it has to cycle. yes, you can see 29C flow, but there is no "gas" icon, that means the boiler is cycling, interesting the boiler turns the pump off so cooling down takes a long time. The main problem with those boilers is minimum delivery, which is 7.5kW for my boiler with 5kW maximum house demand, with "fantastic work" by a plumber done to zone everything with microbore also. Anyway, main point, how ugly and user unfriendly the Vaillant controls are!!! My £40 DIY controls are much more flexible and better. It is absolutely astonishing at what length Vaillant group goes to prevent other ebus implementations to lock to their ugly proprietary controls. Why do you need "weather compensation"? Let me guess, because your controls absolutely rubbish. My thermometer tracks temperature inside rooms with delta 0.01C and sub 10s intervals, I can adjust the flow temperature just based on that and inertia of the system, I can see less demand based on more sun or more demand in a windy day. But heat geeks are keep pushing for those manufacture controls, who just sucks at everything that is not rectangular white box :-(
I did similar with mine, I took our out dated oil boiler out and fitted LPG Vaillant, same split system.
Can't for the life of me understand you installing air source. £2.50 a day for your heating... what is the point of going to the bother or Air Source.
Air source will be pretty much free to run - or even better - after PV export I will have money left in my pocket - so zero bills home
@@UrbanPlumbers not in winter 2kwh per 1kw solar on a sunny day 9 jan,
Dec Avg 0.5 kwh per 1kw of solar
dec i have 10kw system total kwh for the month 160
@@ecoterrorist1402I think he's referring to seasonal offsetting.
Export as much as you can through the good months on a strong tariff like octopus flux to build up the credit to cover you through the winter on a decent import tariff like octopus tracker.
That's some black magic going on. An incredibly low temp flow rate from a regular boiler whose minimum is supposed to be just below 5kw. So the hack allows the boiler to operate well below it's factory minimum output, would be handy to see how that's wired up?
No magic, boiler just cycles a lot ;)
alpha cd25 dial set mid way setting 6 9th Jan 2.6 avg 118kwh Gas UFH flow 34 UFH return 28 160sqm home bungalow 1930 EPC A+ 108 points heating on 24/7 room temp 22
roll on planning so i can install a heat pump
Heat pump load calculated for a Vaillant aroTHERM plus 7
The Outside Design Temperature for postcode NR7 is -2.4°C
At the Outside Design Temperature and a Flow Temperature of 35 °C the output power of the heat pump is 8940 W.
The heat loss from the building at the Outside Design Temperature is expected to be 6600 W.
The total area of the building is 158.15 m2, giving an average heat loss of 42 W/m2.
My 14 year old BG 330+ boiler is costing me about £11 per day.
What size property and build year?
@@UrbanPlumbers 3 bed detached 60s/ 70s home, Thinking I have a massive heat loss issue cold wind blowing through extension light switches and under bedroom doors.
£1.40 first hour this morning.
I wonder what the minimum power of a heat pump is while it's operating. A quick search suggests that the Glow Worm has over 7kW minimum; quite poor. I think Viessmann boilers go down to maybe 3kW or lower for the min power specification. Of course I'm thinking in terms of avoiding on/off cycling here.
Heat pumps modulate down to around 20% of max capacity.
Viessmann 200 modulates down to 1.9KW.
There are some boilers that modulate down to 3KW.
Low modulation is key even with a V200W mine will cycle when outside ambient is 10C or above. So if I had a boiler that modulated to 3KW it would be cycling at 6C and above, modulating at 4KW would by cycling at 3C and above and modulating at 7KW for my house would be cycling at -3C possibly colder.
@normanboyes4983 1.9kW is 70% of my heat loss - my heat pump modulates to 1.5kw
@@UrbanPlumbers That’s an enviable position to be in.👍 (I reckon my heat loss at -2C is likely 6KW 🥲).
@@UrbanPlumbersI remember you saying that most houses have no more than 6-10kwhr heat loss, so 1.5kw will give great turndown ratio and control.
The days of blasting the system with too much power should be gone with good heat loss calculations.
A thing lacking in the trade unfortunately.
Valiant 812 system boiler with wether compensation and full Valiant controls etc. UFH in new part downstairs and there is no way the curve can be set that low, needs to be at around 3.6 and then its want to run at 68 degrees.
How on earth you’ve managed that is amazing, to me me it is anyway
Ufh shouldn’t need more than 50c flow, something not correct with your set up
@@UrbanPlumbers the UFH is via a manifold with a blending valve which i’ve always had set to 55 from memory. The boiler flow is 68 and this shows as the target flow temp from within the config on the wall controller.
But I certainly think you’re correct when you say that the system is working as correctly as it should.
I think you have something weird going on with your system if it is truly on weather compensation an all rad (reasonably sized system on a reasonably well insulated house at - 2C should not need to be targeting above 45C.
@@normanboyes4983 Thanks Norman. What you say us the main reason we went for it, the promise of a nice warm house with the maximum efficiency. I personally think the installer didnt have a complete knowledge of what was being installed. Our problem is that theres no installers nearby who appear competent for hs to employ to setup and or see why its not performing.
@@SME_Ste It is not an uncommon experience unfortunately, heating engineers of Syzmon’s expertise are both busy and scarce. A common mistake is not to have hydraulic separation when running both UFH and Rads - but there are some other poo traps. What part of the country are you in?
Hi Szymon, great to see you back with a new video. Can I ask what controls you used on this set up? I am looking to install a new radiators system and an unvented cylinder to a property and was considering using a glow worm system boiler based on it being £300 cheaper than the Vaillant. I would be interested to know what controls items you would recommend I need to control rads/towel rail circuit/ and 200 litre unvented cylinder in the most energy efficient way. Hope you can help. John 👍
Just use glow worm wiring center and glow worm controls - they are pretty much the same as Vaillabt
Impressively low consumption for a detached house. My 4 bed semi is at 30kWh *input*, at cop around 3.5 at the moment so well over 3x your consumption. Medium/poor insulation :-(
Not so easey with radiators unless you double the size
Or insulate. My radiators are not that big, just well insulated house
Underfloor heating is large surface area, which is hard to match with radiators
@@stevenyates6732 not as difficult as people think - I have done exactly that
It appears you've forgotten about Viessmann 200 boilers which come with everything out of the box. Our customers are paying around £1.5 per day but they are also cheating by using Octopus Gas smart tariffs. Weather comp + unbeatable modulation + insulation = heat pump will struggle to beat it!
Congrats on the house!
yep I have a veissmann 050w which was picked for weather compensation option - and decent modulation ratio. Unfortunately its still a combi boiler so even max modulation means it cycles more than it should, but its a good test for hopefully a future heat pump without too many other changes. I’m paying around the same but am on octopus tracker so only paying 4.5p/kwh which helps.
Yes, but it is Glow Work that costs 1/3 of V200 with £300 vaillant controls and the same performance as v200 ;)
@@UrbanPlumbers I wouldn't say performance is same but definitely an impressive hack!
@@MrKlawUK The 050W isn't comparable the 200 (Much better peak modulation so no cycling, more efficient and has a more advanced type of weather compensation). The 050 is entry level.
For comparison I used 113kwh gas on the 9th, value of £8.69 for that day all in. Martin - Purley.
Yes, but your house is 3 times bigger tak Han mine and also much older and has less insulation. £9 for your house is good.
@@UrbanPlumbers I've been keeping track of daily average costs before and after your install, and the difference is impressive as you predicted :)
All very impressive, but i'm curious what happens when the Hot water tank calls for heat in your setup? Surely flow temp has to rise to well over 60deg to efficiently heat the tank which would also send the same high temp around your rads (assuming room stat also calling for heat) , or have you some kind of temperature regulation / down mixing going on, or is it set up for hot water priority, which effectively pauses flow to rads until HW is satisfied and the VRC raises and lowers the temp accordingly?
Asking because I'm racking my brain looking for the best solution for my ongoing house renovation to make a fairly large house more efficient than it was, spent a fortune on insulation and draught elimination measures so far as well as the building work.
Ground floor zone is (or will be) 100% UFH (pipe in screed), Upper floor zone is all rads, so both zones would work well at this nice low flow temp without the hot/cold cycle of basic on-off which I hate. Yet i also have a 250L HW tank to consider which needs around 70 deg flow temp to get the hot water to around 60/65.
Looking at a new Vailant boiler, and new decent tank with low standing loss (maybe Vailant), 2 Nest stats for zones, Vailant VRC Softcomfort control with weather comp.
you don't use nest with Vaillant, it should be illegal lol
It’s set up on hot water priority so it will only send weather compensation heating into the heating. When hot water is called for you will lose heating for a short amount of time of say 10-20 mins until the hot water cylinder is fully recharged to the set temperature. This is only beneficial with a fast recovery hot water cylinder otherwise you would start to get cold, waiting for the hot water to re generate
It’s PDHw so it doesn’t to CH and DHW at the same time
@@Anthony-dh3ty One of those Marmite things.... I have no complaints about our Nests, works flawless so far and no worse (or better) than other stats on the market but look much nicer in my humble opinion, they just work (and keep working) which is more than I can say for Hive from my direct experience.
What lets our system down is the Vailant boiler itself (a 12 yr old Vailant Ecotec 628 system boiler) the firmware is garbage and widely complained about how it handles modulation under variable load, spends more time cycling in guard mode than anything.
The magic sauce is the Vailant Softcomfort in charge of the boiler (and weather comp), doesn't matter which 'smart' or dumb stat you use then.
@@UrbanPlumbers
So HW Priority ... thought so, thanks.
Would love a video or explanation how you got the VRC and Ideal to play together, I prefer Ideal over Vailant boilers but would like the softcomfort control exactly like you have.
Lucky you in UK 🙂 In Poland we have now -5.6deg C 2 nights ego was -18deg C 🙂
My god im on 348 a month on economy 7 😢
Is that on direct electric?
@@UrbanPlumbers not sure i only have electricity in the property these come on at night
I feel for you. I have a gas boiler, non compensating, and it's currently running at £5/day in the cold weather.
Economy 7 is only for electricity not gas I thought? £348 is That your direct debit amount, what's your actually usage based off of your bills/smart meter.
@@booneyinc9515 1444.7 @ 11.906 Night, 425.9 @ 33.88 Day, 15 ish standing charge
OK now show me the trick of finding an equivalent boiler that runs on heating oil.
Our boiler is the original from when the house was built in 1999 and it definitely needs replacing by now.
Average 3 kw a day using Solar + wood fired heating from own woodland.
It's not a hack. You've got a Vaillant product rebadged as a Glowworm boiler
1.66euros a day burning peat in a Stanley range flow temperature of 65degrees 😂😂😂😂looking at alternative heating sources for the future.
Now this is not a hater comment. If you have your system running that well and that efficiently then why the heat pump. What do you aim to achieve. Your current system is paid for so to spend thousands on heat pump for what.
As I said genuine curiosity not a hater comment. I am sure you have a good reason.
Heat pumps costs me £0 to install after the grant as I do all the work myself. It’s the system (rads, ufh) that costs money and it does need one done to be efficient regardless of the heat source.
Once the heat pump is in place I can then remove gas, don’t pay standing charge and run the heat pump from cheaper tariff or PV - making it pretty much free to run - or even better making money from excess PV sold to the grid.
Keep the gas boiler
Cheaper to run than the heat pump
No, it’s not. My heat pump will be much cheaper to run
@@UrbanPlumbers I can’t see you heating the house and a cylinder of water for less than £2 a day I hope you can because it a big spend to do all that
I’d would probably have duel fuel given a choice
@tonysolley9074 video coming soon. All be reviled and explained
Dont forget, Szymon is a wizard and will probably sqeeze a SCOP of 5.5 out of a heap pump with underfloor heating.
Urban plumbers living in a 80 sqm house, something not adding up.