Found the problem. After changing out the the pilot assembly the start up was fine, however when the fireplace was lit the pilot was slightly starved of gas. The pilot flame wasn't as pronounced and the piezo igniter was splitting the flame. So the thermocouple wasn't getting sufficient flame. I bent the igniter down and over a bit allowing a full flame on the thermocouple, thus solving the the problem. Thanks for your video and response. It definitely helped with the change out.
Originally, they came with wires. The reason they are made the way they are is it makes better contact and can be differentiated from a thermopile. The bare tubing is actually one wire. The other is the insulated wire inside. Hope this helps. GFM
Great video... You can also mention later on that on mv systems, you need a mv thermostat, you cannot hook up a 24 volt thermostat to a mv system. I have not seen that many thermo piles out there, except for old gravity furnaces and occasionally on older boilers.
Good video. Why doesn't the thermocouple just have wires like the thermopile. I never could figure out why the thermocouple has the bare copper tubing.
Dude ! This is exactly what I was looking for. Grandfather was a plumber so my father taught me. Father worked in electronics so he taught me. I was confused though because my gas fireplace has both. Now I even know how to test them. Way Cool ! And at 70, i'm prob way older than you ! LOL Thanks.
May I ask if a water heater thermocouple be the same piece to replace a stove thermocouple? Or does a stove require a different piece all together? Thanks in advance.
I'm about to change the thermopile on my gravity furnace. On the valve I'm not sure which post the red or white wires are supposed to go. Will it damage the thermopile if they are connected to the wrong post?
Hi. I have a 14 year old commercial oven in a restaurant. Pilot light would turn on and turn off. I inspected the pilot light on the burner . Found the thermocouple or pile wiring broken, flame was on it. Replaced the thermocouple. Question is do I have to rest the pilot at the controller. Thanks
My 1999 LP gas Xtrordinair Gas Fireplace takes several minutes sometimes 1/2 hour for the gas valve to open and function when the thermostat is calling for heat, is that a case of a bad thermopile? So called service technicians only seem to come in a replacing everything for $$$ until it works which has happened too many times over the years.
No, We generally do not use amp draw to determine problems with millivolt systems. In practice, if the millivolts are low, the amperage will be low. GFM
@@grayfurnaceman I actually wanted to test it on small LED bulb but no luck. how ever a website claims it produces 1amps at 60 volts @ 200 Celsius heat, so i wanted to know that as well.
I'm able to light my pilot and it will stay on. However, when I turn the knob from Pilot to On, the pilot flame goes out immediately. Would yo suspect the thermopile or thermocoupler as the problem? Or, something else? Thanks
Yes, as I say the pilot does light and will stay on for hours but when you turn the knob from Pilot to ON the flame goes out right away. The gas supply is not the issue. I believe it is the thermopile or thermocoupler.
I have a fireplace insert that started turning on by itself. There is a wall mounted millivolt switch with a pilot light. What steps can I take to find the source of my problem before calling for service? It is a Heat n Glow model ROLS -18N. Thanks in advance.
I have a Heat-n-Glow gas fireplace with a hard wired wall thermostat. It worked fine with the thermostat but now it will not turn the flame on, however, by manually turning the fireplace on and adjusting the temperature up, it will stay on just long enough for the fan to kick on. It then cycles back off without ever coming close to the set room temperature. Thermopile issue?
I have a thermopile on my gas boiler. Yesterday I had to hold the pilot button down for 10 minutes before the pilot would stay lit. Does that mean the thermopile is at the end of it's useful life?
Hello sir. Could you help with one fireplace problem? Cdvr36nv fireplace. Direct-vent. It was shutting down on itself. I checked thermocouple, found that it is weak and everything rusted. I replaced the thermopile/pilot assembly. It was working, then I got a call from the customer. It is working but then again shuts down. I went started checking. Something weird was going on. Pilot was normal but after sometime it became lazy not touching thermocouple. And after sometime shuts down again. I tried to adjust pilot pressure, flame was not changing. Tried checking pilot pressure, no pressure. So I replaced the gas valve. Again the same issue. I am out of the options now 😂 Vent is clean. No idea what's wrong with it. I would think maybe air ports (although I dont know where they are located), but why pilot flame is not changing while adjusting it (on both gas valves) 🤔 Any help will be appreciated. Thanks
I was told that my fireplace was done due to a bad valve and informed that, parts were not available 4k for a new fireplace replacement. I got a second opinion and the thermopile was faulty, got it changed and now the fireplace works fine...
Is the 292 mv enough to pull a gas valve soloniod ? Also is the 30 mv for a thermocouple big enough to pull a solonoid for a gas heater valve to let gas go through ? Thanks for your good video
It depends on whether the voltage is measured with the circuit open or closed. You should be about 500mv open and 125mv closed. The 30 mv will open a gas water valve. That is the only valve I know of that will work with the thermocouple. Hope this helps. GFM
Maybe you can help. I have a late 70's camper with a hydro flame furnace and everything seems right except the pilot won't stay lit, I assume the thermo pile is bad but no one can find one like mine. Mine looks similar to your but the 2 wires go to a screw in fitting like is on all the standard thermocouples. I thought I could just put in a standard thermo couple except the fitting that screws into the valve is too small. The only numbers on my therma pile is a little aluminum tag that says 34R
While the pilot on my Vermont Castings direct vent gas fireplace stays reliably lit, the flame isn't. It goes out after being lit and the time it is fully burning is shortening. I cleaned the unit and two thermopiles, had the unit inspected and it was determined I needed two new thermopiles. They wanted $1,000 for parts plus labor. I purchased two thermopile thermogenerators. Can I install these myself or should I use a gas fitter? I noticed that the wires for the thermopiles pass through a red rubbery sealant. What is this?
what I want to know is, what do you check for if the gas/pilot is lit, but wont go on when the switch is turned on, and knowing that there is power to the switch?
Michael Buttaccio Mostly this is a power problem. The is video may help: ua-cam.com/video/LBXCrk74hlY/v-deo.html Its a little long but should give you some tips. GFM
I need a thermopile for a small gas booster heater. The current one works well enough to run the pilot safety, but not enough output for the thermostat circuit. Local places around here don't have them (most don't seem to have heard of them). You've shown that they are still being made, can you tell me where in the H*!! to get one?
I have a DESA natural gas fireplace. My thermocouple works great because the pilot light stays on when I turn the gas to the on position, but the pilot light goes out when I turn my thermostat on. The thermopile gets up to about 460 millivotes with no load. When I connect it to the gas valve and turn my thermostat on, the pilot light immediately goes out. Do you have and suggestions on hoe to resolve this problem?
You probably have a short to chassis. It would probably be between the thermostat and the valve because it does not fail with the thermostat. If you disconnect the wire from the thermostat to the gas valve at the gas valve, and it still goes off, it is between the valve and the thermostat. Hope this helps. GFM
Diamondssnpr We usually consider 14 the minimum for a thermocouple. Thermopiles should read 4-500 open circuit. That means if the gas valve is not calling for heat. If the gas valve is calling 100-275 is good. Hope this helps. GFM
grayfurnaceman Thanks for getting back so quick, and thanks for making these videos, I'm looking to get into service work soon for plumbing, so i thought i would study up.. CHEERS...
The remote wall switch will not ignite the fireplace. The local switch next to the gas valve will ignite fireplace. What could be the issue. The mV on the terminal board seem to be in the good range when both switches connected. Any help is appreciated.
as a suggestion Make sure the thermostat used is designed for a millivolt system ,, many 24 volt thermostats have resistance in the Tstat itself in the form of a compensator and it lowers the current flow enough so the gas valve wont respond and open when called to deliver heat,
Hi GrayFurnaceMan, I have a 35+ year old gas furnace (Howard Southwind) with a standing pilot light. Furnace works well when running but has intermittent ignition troubles and has taken as long as 30 minutes to start - other times it fires up right away. The worst offending time would be morning when the furnace has been off for the night. The pilot light is always on and is nice and blue. I thought it was the thermostat but have tried 2 other thermostats and the problem persists. Because it is intermittent I thought that the new thermostat was fixing the problem. Inside the furnace the gas valve box has 4 wire screw terminals. It appears that two of them are attached to a thermopile…it has silver coated wire and two clips on the end with a white and red wire. The silver wire runs down to the pilot with a tube threaded into place. I put my multi-meter on the terminals and have a reading of 132 mv while the burners are on full. With the pilot light still on but the burners off…the reading is between 194 and 162 mv. It is difficult to get a solid reading off of the screws themselves. I also tightened the screws. Besides the main gas burner pipe there is another small aluminum tube that runs out of the gas valve box and down to the pilot light. I am not sure if that is also a thermocouple. If I replace the thermopile - how do I know which one to buy? (When I went online to research gas furnace thermopiles almost everything relates back to thermocouples and most images do not have the wires…which my furnace obviously uses. I also see the K type mentioned….but I am not sure what part to order from my HVAC supplier) Most suppliers want to know furnace make and model naturally and here is no literature or manual available for my Furnace. I like my old furnace it has been chugging along perfectly for the last 20 years…the heat exchanger looks good, I recently replaced the blower motor and belt as well as the fan relay switch and filter as part of the maintenance. Thanks for any advice!
The thermopile millivolts appears too low. Should read open circuit around 500 mv. First check all connections to be sure they are tight. Very low voltage here. As an example, a 1.5 volt battery is 1500 mv. You can replace thermocouple with a Honeywell Q313A1188 or equivalent. That is pretty much the standard type used in most appliances. Hope this helps. GFM
My new gas fireplace has both. Pilot in the middle with thermopile on one side and thermocouple on the other. The flame touches both. The fireplace goes out after a few minutes. Any idea what I should do to trouble shoot this issue?
The thermocouple is a safety shutdown. The thermopile is a power source for the fireplace. Is the pilot covering both the thermopile and the thermocouple? If the pilot goes out when the fireplace shuts down, your problem is in the safety shutdown system. If the pilot does not shut down, the problem is in the power source. If the pilot goes out, the thermocouple is probably the failure. If the pilot does not go out, be sure all connections are clean and tight. Let me know if you are still stuck. GFM
Gray Furnaceman I always have to manually turn on my fireplace it has the thermopile system I use the igniter to turn on the pilot then I wait for the fireplace to light up sometimes it takes days and then it just keeps burning until I close the gas valve any thoughts of what I can do to correct this problem before calling in a repairman
If it was just a problem with the burner lighting off, I would say you have thermopile problem. However, if it stays on, I would have to blame the gas valve. GFM
@@grayfurnaceman I'd be tempted to say that it could be both the thermopile and valve. That's a spendy repair. I just diagnosed a bad valve. Always a good idea to test it with a new thermopile first to make sure.
+GFM I have an outdoor thermometer, simply for outdoor temp readings while getting dressed in the morning. I have placed it out of the shade every way I can think of, but I am still getting false readings because of the sun. I have tried wrapping the thermocouple in aluminum foil and I have tried shading it even more so than it already is. I have tried tucking it beneath the vinyl siding, but still get false readings. the digital display is accurate at night and in a cup of ice water. do you have any thoughts on how to prevent false measurements? I am limited to about 10' of wire between the display and the thermocouple. thanks
If it is a thermopile controlled system, you could have a loose connection or the thermopile output could be low. Be sure the pilot is blue and covering the thermopile. Open circuit millivolts should be 500 if you test with a meter. Hope this helps. GFM
I was wondering if you could tell me a little about how the old large pizza oven temp controllers work. Its old and has no external electricity hooked up. Just a copper temp sensing probe attached by what looks like a copper capillary very similar in appearance to a thermocouple.
I have no experience with these controllers. I could very well be a thermocouple, or it could be a mercury filled probe. Does it have and end that looks just like a thermocouple with a smaller tube to the control itself. If you want to send a pic, I will try. GFM
grayfurnaceman The temp probe is more like a small capillary tube with a 1/4" x 8" strait tube on the end. The valve itself has a dial that goes up to 500F to control the temp of the oven. All of the various components are separate and plumbed together with pipe. The safety valve seems to work, I push and hold the button and light the pilot and eventually I can let go of the button and the pilot will stay lit. The next component is the shut off valve then the temp control valve. I will see if I can get a picture.
Richard Keith What you probably have is a hydraulic temp control with a pilot safety. They use the expansion of the hydraulic fluid to control the amount of gas to the burner. Hope this helps. GFM
@@grayfurnaceman thanks for the answer, i quess even if it has that stuff it can't get out of there right ? or if it did the thermostat wouldnt work anymore ? i bought mine last year so i guess it is safe....i dont want that stuff in my house...model is eurosit 630 that i have
We'll I tried new thermo couple still no luck only lights on the manual side of the switch the stove shop said it could be the gas valve but has been discontinued becouse the stove is 15 years old
Ok so I guess you know if the pile is the problem or the couple by the volt test? Does the appliance have a badge with the details or is this industry standard knowledge across the board?
I've run into a problem with my boiler, I have only been living in the house one year, so last year I called a company and they charged me way too much and did very little. The guy told me one of my boilers out of three needed to be replaced at the tune of 10 grand. But I called another and that guy said a couple thousand and then another said a couple hundred. I wasn't sure what to do so I looked on line. I came up with the pressure was building because the pigtail copper tube was plugged up so I took it off and cleaned it out and it solved that problem. But the pilot would light but it would go out after the cycle finished. All the signs pointed to the pilot generator from what I could get people to say so I replaced it and yet the problem remained.From there I called a pro and he replaced the gas valve and then it would do the same as before. He then said I needed a new pressure switch and replaced that and yet it still did the same thing. But after a few weeks I did get it to function correctly but it would go out from time to time. What I did was adjust the setting on the pressure switch up and down one half turn at a time and that got me through the winter without too much trouble but annoying. But this year I'm not getting it to work and a guy from the gas service company who had come to change one of the meters, told me my thermopile needed replacing. So I replaced it and no it didn't do it. So I'm stuck, and I just don't trust any of these people here in the Boson area. Is there anything you can suggest that might solve my problem? I don't mind paying someone for their assistance but I'm not about to call someone else out to guess how much money I have in my wallet. I told one guy that I'll pay to get it fixed but not to replace what I've already replaced so he wasn't interested.
+Dennis Robinson The situation seems quite cloudy. There probably is no thermopile as the boiler must be fairly new. Newer boilers do not have thermopiles or thermocouples. Give the model and make and I will see what I can do. GFM
Thank you sir for getting back with me so quickly. But actually the furnace is an older model Burnham 404 B ANS 221-13 1988 85,000 btu low pressure boiler My other two boilers are Burnham but a bit newer units with autolight pilots. I've looked at the wires for the pressure switch and the auto water filler and even cut and restriped the wires and connected them again but to no avail. The thing that gets me is last winter I would adjust the screw on the pressuretrol cut in switch a quarter turn here and there and it would work for a few weeks and then I'd do it again and after a couple times it would work again for a few weeks. It just doesn't make sense but something is amiss. I was thinking about rewiring everything with new wiring and see if that could solve the problem.that boiler is sound, doesn't' leak and the pilot will stay on and I can turn it on and it will heat up and come to temperature but when after it cycles the pilot goes out, but I can turn it on and then turn it back to pilot and it will stay lit and turn it back on and back to pilot and it stays lit. But that is why I'm baffled. so the only thing left is to put new wiring for the pressure switch and the water auto switch. I also replaced the thermostat here recently because I didn't want to leave any stone unturned. I do appreciate any assistance you can give with this matter. sincerely Dennis Robinson.
+Dennis Robinson If the pilot goes out when the flame extinguishes, about the only thing I can think of is to install a Honeywell S86 intermittent pilot assembly. This will eliminate the standing pilot and only light the pilot when there is a call for heat. GFM
yes, that seems like the only logical answer, thank you for your expert advice. I'll look into it today and get one sent to me asap. Good fortune for you and yours and Happy Thanksgiving, we do have much to be thankful for.
I've looked into that but can't see how it would light the pilot without a flame. When the pilot flame goes out I have to use a lighter to get it lit. I'd have to have a set up like in the other two units, but they're a bit wider and have the room for the gas valve autopilot combination to fit. But I know there has to be a way to repair this one. So thanks again for your assistance but I'm going to figure this out and not let it beat me. After many hours spent last year I was able to get it working so I'm sure as I stay at it I'll get it done. Thanks sincerely for your advice
Really enjoyed your video and have some questions regarding a recent repair I performed on a Heat-n-Glo gas fireplace. I was having problems with the fireplace when I turned it off in the evening it would snuff out the pilot light. Relighting the pilot became progressively worse. This went on for several weeks so I decided to replace the pilot light assembly that contained a thermocouple, thermopile and Piezo. I replaced it today and achieved a nice blue flame on the pilot, however cant seem to keep it going for more than 8 minutes before I hear a click in the valve assembly cutting off the flame and the pilot light. The pilot will restart after a few minutes. I feel confident I made the repair correctly. Did I repair the wrong part, should I have replace the valve assembly instead? Your thoughts would be most appreciated. Thanks
The original problem probably has nothing to do with the pilot lite unless it was very small or the flame was yellow. These type problems usually have to do with the propagation of the flame. Its usually a question of moving the particles that the flame goes thru. As for the replacement pilot, is the flame covering the thermopile and thermocouple? Are all the thermopile and thermocouple connections tight? GFM
Be on the lookout for improper thermostats with millivolt systems ,, the compensator in a normal 24 volt "mechanical" thermostat creates resistance in the circuit , this thermostat might work with a brand new thermopile but as they weaken slightly with age you will end up with not enough current flow to open the gas valve .. the thermostat must be designed for millivolt ,, and not have a resistive compensator in the circuit,, had a gas fireplace that would work fine in the "on" position ,, but not work when in the Tstat position (not enough current due to thermostat being the wrong type) thermopile itself tested around 550 millivolts , replacing the thermopile with a new one would be a temp fix due to the new thermopile being slightly stronger when its brand new but the core fault was "thermostat wrong type"..
You are correct. If it is not a millivolt thermostat sometimes they work and sometimes they don't. A Lot of fireplaces are set up with 24 volt thermostats. GFM
I have a gas fire place my stove will light manually when I flip the switch but won't light with the thermostat . pilot is working once stove manually starts and I flip the switch to thermostat it will run and shut off when it reaches set temp but will not restart when temp in house drops it's millivolt system if I disconnect the two wires put them together and start the stove flip it to thermostat will stay running separate the wires it shuts off any ideas would be great even tried new thermostat no luck thanks for your time
Are you using an electronic thermostat? Also is the thermostat a millivolt thermostat? There is a difference. Also make sure all terminals are clean and tight. Hope this helps. GFM
It is a millivolt thermostat battery power electronic I've changed wiring everything is tight and new battery's I'm baffled worked fine last year when I restated this year when the problem started changed thermal couple about three years old never changed thermal pile stove is about 15 years old Vermont castings radiance stove thanks for your time and writing back
grayfurnaceman This is typically what gets them in this situation, you cannot bake them into submission, They require a cool end and a hot end, not 2 hot ends,A temperature differential is what makes the dissimilar metals create the 3/4 volt or 750mv. 750mv systems are easily troubleshot with a AAA battery in a Radio Shack battery holder with alligator clip leads, or just a battery and wire taped on each end of the battery to simulate a good flame signal, a battery is more than 750mv but at this level it will not hurt a thing to put 1.5 v to a 750mv system. Keep in mind a 750mv system often uses low voltage wiring to its stat, a tarnish or patina or moisture etc can easily disrupt this, the current flows outside the wiring and that is enough to make the stat quit operating. get the wire shiny at both ends, floor furnces did this alot, with the prices of a tcouple and tple, you are doing nobody any favors by leaving one in if already therem trust me a call back on a millivolt system is embarrassing to me but they can actually be tough if you do not think with a fine touch, like clean wires no tarnish etc, and test with a battery and replace serviceable parts like the pilot safetys You only want the flame impinging upon the top 1/3 to 1/2 at most or risk this type of stuff.
My land lord purchased a Whirlpool nautral gas hot water heater. This was a brand new water heater that was purchased from Lowes. The plumber hooked it up and it wouldn't fire. The thermal switch was broken. So since Thursday evening I have had no hot water. Isn't there a way to force light the water heater? Why doesn't the government force Honeywell to stop making those worthless electronic gas valves.
altlandf You can thank government agencies for that. Water heaters have been changed for safety issues. There is no way to force them. Manufacturers make what passes safety regulations. GFM
This electronic valve has a major design flaw. There's nothing wrong with the old school no electronic valve. If you get the 4 flashedes on the Honeywell valve it's done. Another thing why don't plumbers have this part? Why would they not be able to get them locally? www.tylertork.com/qna/2013/gasvalve talks about all the issues with these worthless electronic valves. This is bullshit.
Found the problem. After changing out the the pilot assembly the start up was fine, however when the fireplace was lit the pilot was slightly starved of gas. The pilot flame wasn't as pronounced and the piezo igniter was splitting the flame. So the thermocouple wasn't getting sufficient flame. I bent the igniter down and over a bit allowing a full flame on the thermocouple, thus solving the the problem. Thanks for your video and response. It definitely helped with the change out.
Glad you got it going.
GFM
Originally, they came with wires. The reason they are made the way they are is it makes better contact and can be differentiated from a thermopile. The bare tubing is actually one wire. The other is the insulated wire inside. Hope this helps.
GFM
Thank you for the info. I didn't understand the difference between the two until now.
Welcome
GFM
Great video... You can also mention later on that on mv systems, you need a mv thermostat, you cannot hook up a 24 volt thermostat to a mv system. I have not seen that many thermo piles out there, except for old gravity furnaces and occasionally on older boilers.
Thank you for your nicely shot vids! Very helpful in understanding my ancient system :-)
What's the solenoid current required for holding the pilot valve? The thermocouple output voltage is only 30mV!
Good video. Why doesn't the thermocouple just have wires like the thermopile. I never could figure out why the thermocouple has the bare copper tubing.
There will be more on the thermopile system.
GFM
Thanks. Sounds like a thermopile is a battery of thermocouples in series.
You got it.
GFM
Finally got it working thanks for all your help
Dude ! This is exactly what I was looking for. Grandfather was a plumber so my father taught me. Father worked in electronics so he taught me. I was confused though because my gas fireplace has both. Now I even know how to test them. Way Cool ! And at 70, i'm prob way older than you ! LOL
Thanks.
Great video, actual demonstration with meter.
May I ask if a water heater thermocouple be the same piece to replace a stove thermocouple? Or does a stove require a different piece all together? Thanks in advance.
Water heater thermocouples are the same as furnace thermocouples, they are generally just shorter.
GFM
@@grayfurnaceman thank you so much!
Is the controller from a gas fryer?
I'm about to change the thermopile on my gravity furnace. On the valve I'm not sure which post the red or white wires are supposed to go. Will it damage the thermopile if they are connected to the wrong post?
It makes no difference.
GFM
Thanks for your reply. I put in the thermopile on a furnace that hasn't ran in over 15 years, now I finally got flame.@@grayfurnaceman
Hi. I have a 14 year old commercial oven in a restaurant. Pilot light would turn on and turn off. I inspected the pilot light on the burner . Found the thermocouple or pile wiring broken, flame was on it. Replaced the thermocouple. Question is do I have to rest the pilot at the controller.
Thanks
I am not sure what you mean by "rest the pilot".
GFM
My 1999 LP gas Xtrordinair Gas Fireplace takes several minutes sometimes 1/2 hour for the gas valve to open and function when the thermostat is calling for heat, is that a case of a bad thermopile? So called service technicians only seem to come in a replacing everything for $$$ until it works which has happened too many times over the years.
Could be a dirty pilot a bad thermocouple or most likley if your using a manual on off switch to turn the unit on thats ur issue.
can you tell me how many amps does that thermopile produces?
No, We generally do not use amp draw to determine problems with millivolt systems. In practice, if the millivolts are low, the amperage will be low.
GFM
@@grayfurnaceman I actually wanted to test it on small LED bulb but no luck. how ever a website claims it produces 1amps at 60 volts @ 200 Celsius heat, so i wanted to know that as well.
I'm able to light my pilot and it will stay on. However, when I turn the knob from Pilot to On, the pilot flame goes out immediately. Would yo suspect the thermopile or thermocoupler as the problem? Or, something else? Thanks
Are you sure you have gas available?
GFM
Yes, as I say the pilot does light and will stay on for hours but when you turn the knob from Pilot to ON the flame goes out right away. The gas supply is not the issue. I believe it is the thermopile or thermocoupler.
I have a fireplace insert that started turning on by itself. There is a wall mounted millivolt switch with a pilot light. What steps can I take to find the source of my problem before calling for service? It is a Heat n Glow model ROLS -18N. Thanks in advance.
I have a Heat-n-Glow gas fireplace with a hard wired wall thermostat. It worked fine with the thermostat but now it will not turn the flame on, however, by manually turning the fireplace on and adjusting the temperature up, it will stay on just long enough for the fan to kick on. It then cycles back off without ever coming close to the set room temperature. Thermopile issue?
I would certainly be checking the thermopile. Also all wiring connections, clean and tight.
GFM
Thanks for the knowledge
I have a thermopile on my gas boiler. Yesterday I had to hold the pilot button down for 10 minutes before the pilot would stay lit. Does that mean the thermopile is at the end of it's useful life?
cottagestreetgirl probably if the pilot is clean. Or it could be the wire connections have to be cleaned
Hello sir. Could you help with one fireplace problem? Cdvr36nv fireplace. Direct-vent. It was shutting down on itself. I checked thermocouple, found that it is weak and everything rusted. I replaced the thermopile/pilot assembly. It was working, then I got a call from the customer. It is working but then again shuts down. I went started checking. Something weird was going on. Pilot was normal but after sometime it became lazy not touching thermocouple. And after sometime shuts down again. I tried to adjust pilot pressure, flame was not changing. Tried checking pilot pressure, no pressure. So I replaced the gas valve. Again the same issue. I am out of the options now 😂 Vent is clean. No idea what's wrong with it. I would think maybe air ports (although I dont know where they are located), but why pilot flame is not changing while adjusting it (on both gas valves) 🤔 Any help will be appreciated. Thanks
I was told that my fireplace was done due to a bad valve and informed that, parts were not available 4k for a new fireplace replacement. I got a second opinion and the thermopile was faulty, got it changed and now the fireplace works fine...
Sometimes I just don't get it. Some techs just don't want to repair anything. Glad you got the second opinion.
GFM
Thanks
GFM
Is the 292 mv enough to pull a gas valve soloniod ? Also is the 30 mv for a thermocouple big enough to pull a solonoid for a gas heater valve to let gas go through ? Thanks for your good video
It depends on whether the voltage is measured with the circuit open or closed. You should be about 500mv open and 125mv closed. The 30 mv will open a gas water valve. That is the only valve I know of that will work with the thermocouple. Hope this helps.
GFM
Nice video Gray.
Well, you can put them on, but they won't work right! Thanks for the thoughts.
GFM
Maybe you can help. I have a late 70's camper with a hydro flame furnace and everything seems right except the pilot won't stay lit, I assume the thermo pile is bad but no one can find one like mine. Mine looks similar to your but the 2 wires go to a screw in fitting like is on all the standard thermocouples. I thought I could just put in a standard thermo couple except the fitting that screws into the valve is too small. The only numbers on my therma pile is a little aluminum tag that says 34R
@@yamaharider7672 You might try this one: www.amazon.com/Thermopile-Pilot-Adaptor-Coaxial-Long/dp/B003A1YFF2
GFM
While the pilot on my Vermont Castings direct vent gas fireplace stays reliably lit, the flame isn't. It goes out after being lit and the time it is fully burning is shortening. I cleaned the unit and two thermopiles, had the unit inspected and it was determined I needed two new thermopiles. They wanted $1,000 for parts plus labor. I purchased two thermopile thermogenerators. Can I install these myself or should I use a gas fitter? I noticed that the wires for the thermopiles pass through a red rubbery sealant. What is this?
If you are confident, you can replace them. The sealant is probably high temp silicone. You can get it at a hardware store.
GFM
IKe pilot on my gas fireplace will not stay on for more than 10 minutes then shuts off. What is it's problem?
Some fireplaces have a limit switch that will shut down the pilot system if the fireplace overheats. Could mean the unit is overfired.
GFM
I will let u know how I make out this week thanks for your time patience
what I want to know is, what do you check for if the gas/pilot is lit, but wont go on when the switch is turned on, and knowing that there is power to the switch?
Michael Buttaccio Mostly this is a power problem. The is video may help: ua-cam.com/video/LBXCrk74hlY/v-deo.html Its a little long but should give you some tips.
GFM
grayfurnaceman Thanks, but I think you gave me the wrong video to watch?? I live in Vegas by the way
I need a thermopile for a small gas booster heater. The current one works well enough to run the pilot safety, but not enough output for the thermostat circuit. Local places around here don't have them (most don't seem to have heard of them). You've shown that they are still being made, can you tell me where in the H*!! to get one?
+diggerop Heating contractors should have them. Or there are plenty of sources on the internet. Hope this helps.
GFM
I have a DESA natural gas fireplace. My thermocouple works great because the pilot light stays on when I turn the gas to the on position, but the pilot light goes out when I turn my thermostat on. The thermopile gets up to about 460 millivotes with no load. When I connect it to the gas valve and turn my thermostat on, the pilot light immediately goes out. Do you have and suggestions on hoe to resolve this problem?
You probably have a short to chassis. It would probably be between the thermostat and the valve because it does not fail with the thermostat. If you disconnect the wire from the thermostat to the gas valve at the gas valve, and it still goes off, it is between the valve and the thermostat. Hope this helps.
GFM
Mine on my millivolt system is putting out about 700 millivolts and the tip of the thermopile is glowing red a little. Is the pilot set to high?
It should be ok. If you want to reduce it you can, but be sure the millivolts are up.
GFM
grayfurnaceman Thanks so much! Your videos are super helpful.
Bib Drums Welcome
GFM
under what reading would be considered a bad reading for a thermopile.
Is under 24 millivolts a circumstance for replacing a thermocouple.
Diamondssnpr We usually consider 14 the minimum for a thermocouple. Thermopiles should read 4-500 open circuit. That means if the gas valve is not calling for heat. If the gas valve is calling 100-275 is good. Hope this helps.
GFM
grayfurnaceman Thanks for getting back so quick, and thanks for making these videos, I'm looking to get into service work soon for plumbing, so i thought i would study up.. CHEERS...
The remote wall switch will not ignite the fireplace. The local switch next to the gas valve will ignite fireplace. What could be the issue. The mV on the terminal board seem to be in the good range when both switches connected. Any help is appreciated.
+William Anacker Connections are very important with millivolt systems. Be sure all connections are tight. If no help, replace the switch.
GFM
as a suggestion Make sure the thermostat used is designed for a millivolt system ,, many 24 volt thermostats have resistance in the Tstat itself in the form of a compensator and it lowers the current flow enough so the gas valve wont respond and open when called to deliver heat,
I have a 90 model floor furnace. Pilot light stays light. Changed relays and thermostat. Still will on come on.Any suggestions?
Is it a millivolt system?
GFM
Hi GrayFurnaceMan, I have a 35+ year old gas furnace (Howard Southwind) with a standing pilot light. Furnace works well when running but has intermittent ignition troubles and has taken as long as 30 minutes to start - other times it fires up right away. The worst offending time would be morning when the furnace has been off for the night. The pilot light is always on and is nice and blue. I thought it was the thermostat but have tried 2 other thermostats and the problem persists. Because it is intermittent I thought that the new thermostat was fixing the problem. Inside the furnace the gas valve box has 4 wire screw terminals. It appears that two of them are attached to a thermopile…it has silver coated wire and two clips on the end with a white and red wire. The silver wire runs down to the pilot with a tube threaded into place. I put my multi-meter on the terminals and have a reading of 132 mv while the burners are on full. With the pilot light still on but the burners off…the reading is between 194 and 162 mv. It is difficult to get a solid reading off of the screws themselves. I also tightened the screws. Besides the main gas burner pipe there is another small aluminum tube that runs out of the gas valve box and down to the pilot light. I am not sure if that is also a thermocouple. If I replace the thermopile - how do I know which one to buy? (When I went online to research gas furnace thermopiles almost everything relates back to thermocouples and most images do not have the wires…which my furnace obviously uses. I also see the K type mentioned….but I am not sure what part to order from my HVAC supplier) Most suppliers want to know furnace make and model naturally and here is no literature or manual available for my Furnace. I like my old furnace it has been chugging along perfectly for the last 20 years…the heat exchanger looks good, I recently replaced the blower motor and belt as well as the fan relay switch and filter as part of the maintenance. Thanks for any advice!
The thermopile millivolts appears too low. Should read open circuit around 500 mv. First check all connections to be sure they are tight. Very low voltage here. As an example, a 1.5 volt battery is 1500 mv. You can replace thermocouple with a Honeywell Q313A1188 or equivalent. That is pretty much the standard type used in most appliances. Hope this helps.
GFM
My new gas fireplace has both. Pilot in the middle with thermopile on one side and thermocouple on the other. The flame touches both.
The fireplace goes out after a few minutes. Any idea what I should do to trouble shoot this issue?
The thermocouple is a safety shutdown. The thermopile is a power source for the fireplace.
Is the pilot covering both the thermopile and the thermocouple?
If the pilot goes out when the fireplace shuts down, your problem is in the safety shutdown system.
If the pilot does not shut down, the problem is in the power source.
If the pilot goes out, the thermocouple is probably the failure.
If the pilot does not go out, be sure all connections are clean and tight.
Let me know if you are still stuck.
GFM
@@grayfurnaceman Thermocouple completely. Thermopile only partly.
What does the thermopile power exactly?
@@jamescahill3390 About 2/3 of the thermopile should be covered. It powers the gas controls.
GFM
Gray Furnaceman
I always have to manually turn on my fireplace it has the thermopile system
I use the igniter to turn on the pilot then I wait for the fireplace to light up sometimes it takes days and then it just keeps burning until I close the gas valve any thoughts of what I can do to correct this problem before calling in a repairman
If it was just a problem with the burner lighting off, I would say you have thermopile problem. However, if it stays on, I would have to blame the gas valve.
GFM
@@grayfurnaceman
I'd be tempted to say that it could be both the thermopile and valve. That's a spendy repair. I just diagnosed a bad valve. Always a good idea to test it with a new thermopile first to make sure.
How long will that little propane torch run on a single canister?
+Jeremy Voshage Its refillable. It seems to go forever but then I don't use it that much
GFM
You need to be more specific. There are few induced appliances that use a thermopile. Let me know.
GFM
That would be my thought also.
GFM
+GFM I have an outdoor thermometer, simply for outdoor temp readings while getting dressed in the morning. I have placed it out of the shade every way I can think of, but I am still getting false readings because of the sun. I have tried wrapping the thermocouple in aluminum foil and I have tried shading it even more so than it already is. I have tried tucking it beneath the vinyl siding, but still get false readings. the digital display is accurate at night and in a cup of ice water.
do you have any thoughts on how to prevent false measurements? I am limited to about 10' of wire between the display and the thermocouple. thanks
Not much you can do without moving it to where the sun can't reflect on it.
GFM
grayfurnaceman thanks for getting back to me....guess I'll keep moving it around and trying new spots. take care
Thanks. More coming on fireplaces.
GFM
wondering if you could give me a little help my fireplace keeps going out but the pilot light stays on
If it is a thermopile controlled system, you could have a loose connection or the thermopile output could be low. Be sure the pilot is blue and covering the thermopile. Open circuit millivolts should be 500 if you test with a meter. Hope this helps.
GFM
How long do thermocouples/thermopiles last in service?
They are quite dependable. An average would be at least 20 years.
GFM
Years. Lot longer than glow rods.
Can I replace a thermocouple for a thermopile in the same gas log fireplace? Thanks
No, they are completely different parts.
GFM
I was wondering if you could tell me a little about how the old large pizza oven temp controllers work. Its old and has no external electricity hooked up. Just a copper temp sensing probe attached by what looks like a copper capillary very similar in appearance to a thermocouple.
I have no experience with these controllers. I could very well be a thermocouple, or it could be a mercury filled probe. Does it have and end that looks just like a thermocouple with a smaller tube to the control itself. If you want to send a pic, I will try.
GFM
grayfurnaceman The temp probe is more like a small capillary tube with a 1/4" x 8" strait tube on the end. The valve itself has a dial that goes up to 500F to control the temp of the oven. All of the various components are separate and plumbed together with pipe. The safety valve seems to work, I push and hold the button and light the pilot and eventually I can let go of the button and the pilot will stay lit. The next component is the shut off valve then the temp control valve. I will see if I can get a picture.
Richard Keith What you probably have is a hydraulic temp control with a pilot safety. They use the expansion of the hydraulic fluid to control the amount of gas to the burner. Hope this helps.
GFM
Thank you GFM.
Hello sir, do the gas oven thermostats contain Mercury? I have Eurosit 630
If they were made in the 1980s or earlier, they could have.
GFM
@@grayfurnaceman thanks for the answer, i quess even if it has that stuff it can't get out of there right ? or if it did the thermostat wouldnt work anymore ? i bought mine last year so i guess it is safe....i dont want that stuff in my house...model is eurosit 630 that i have
@@Ask8erM I would not guarantee it could not get out. The unit would not work if the mercury leaked out. Yours is probably safe.
GFM
At 3:32 did you mean to say thermopile instead of thermocouple?
Scott Wade Its thermopile. Thanks for pointing that out.
GFM
Will the pilot stay lit with a defective thermopile?
No.
GFM
Thank you
Thank you Sir! I learned a lot!
We'll I tried new thermo couple still no luck only lights on the manual side of the switch the stove shop said it could be the gas valve but has been discontinued becouse the stove is 15 years old
Did you replace the thermocouple or the thermopile?
GFM
Make one on induced furnaces
The Thermopile is an over temp cut out probe?
No. It is a power source to operate the gas controls.
GFM
Hey cool thanks
Ok so I guess you know if the pile is the problem or the couple by the volt test? Does the appliance have a badge with the details or is this industry standard knowledge across the board?
I've run into a problem with my boiler, I have only been living in the house one year, so last year I called a company and they charged me way too much and did very little. The guy told me one of my boilers out of three needed to be replaced at the tune of 10 grand. But I called another and that guy said a couple thousand and then another said a couple hundred. I wasn't sure what to do so I looked on line. I came up with the pressure was building because the pigtail copper tube was plugged up so I took it off and cleaned it out and it solved that problem. But the pilot would light but it would go out after the cycle finished. All the signs pointed to the pilot generator from what I could get people to say so I replaced it and yet the problem remained.From there I called a pro and he replaced the gas valve and then it would do the same as before. He then said I needed a new pressure switch and replaced that and yet it still did the same thing. But after a few weeks I did get it to function correctly but it would go out from time to time. What I did was adjust the setting on the pressure switch up and down one half turn at a time and that got me through the winter without too much trouble but annoying. But this year I'm not getting it to work and a guy from the gas service company who had come to change one of the meters, told me my thermopile needed replacing. So I replaced it and no it didn't do it. So I'm stuck, and I just don't trust any of these people here in the Boson area. Is there anything you can suggest that might solve my problem? I don't mind paying someone for their assistance but I'm not about to call someone else out to guess how much money I have in my wallet. I told one guy that I'll pay to get it fixed but not to replace what I've already replaced so he wasn't interested.
+Dennis Robinson The situation seems quite cloudy. There probably is no thermopile as the boiler must be fairly new. Newer boilers do not have thermopiles or thermocouples. Give the model and make and I will see what I can do.
GFM
Thank you sir for getting back with me so quickly. But actually the furnace is an older model Burnham 404 B ANS 221-13 1988 85,000 btu low pressure boiler
My other two boilers are Burnham but a bit newer units with autolight pilots.
I've looked at the wires for the pressure switch and the auto water filler and even cut and restriped the wires and connected them again but to no avail. The thing that gets me is last winter I would adjust the screw on the pressuretrol cut in switch a quarter turn here and there and it would work for a few weeks and then I'd do it again and after a couple times it would work again for a few weeks.
It just doesn't make sense but something is amiss. I was thinking about rewiring everything with new wiring and see if that could solve the problem.that boiler is sound, doesn't' leak and the pilot will stay on and I can turn it on and it will heat up and come to temperature but when after it cycles the pilot goes out, but I can turn it on and then turn it back to pilot and it will stay lit and turn it back on and back to pilot and it stays lit. But that is why I'm baffled. so the only thing left is to put new wiring for the pressure switch and the water auto switch. I also replaced the thermostat here recently because I didn't want to leave any stone unturned.
I do appreciate any assistance you can give with this matter.
sincerely Dennis Robinson.
+Dennis Robinson If the pilot goes out when the flame extinguishes, about the only thing I can think of is to install a Honeywell S86 intermittent pilot assembly. This will eliminate the standing pilot and only light the pilot when there is a call for heat.
GFM
yes, that seems like the only logical answer, thank you for your expert advice. I'll look into it today and get one sent to me asap. Good fortune for you and yours and Happy Thanksgiving, we do have much to be thankful for.
I've looked into that but can't see how it would light the pilot without a flame. When the pilot flame goes out I have to use a lighter to get it lit. I'd have to have a set up like in the other two units, but they're a bit wider and have the room for the gas valve autopilot combination to fit. But I know there has to be a way to repair this one. So thanks again for your assistance but I'm going to figure this out and not let it beat me. After many hours spent last year I was able to get it working so I'm sure as I stay at it I'll get it done.
Thanks sincerely for your advice
Thank you, Sir.
Welcome
GFM
It's only hitting the front half ands it has a gray color to it thanks
I would clean the pilot assembly
Great video
Really enjoyed your video and have some questions regarding a recent repair I performed on a Heat-n-Glo gas fireplace. I was having problems with the fireplace when I turned it off in the evening it would snuff out the pilot light. Relighting the pilot became progressively worse. This went on for several weeks so I decided to replace the pilot light assembly that contained a thermocouple, thermopile and Piezo. I replaced it today and achieved a nice blue flame on the pilot, however cant seem to keep it going for more than 8 minutes before I hear a click in the valve assembly cutting off the flame and the pilot light. The pilot will restart after a few minutes. I feel confident I made the repair correctly. Did I repair the wrong part, should I have replace the valve assembly instead? Your thoughts would be most appreciated. Thanks
The original problem probably has nothing to do with the pilot lite unless it was very small or the flame was yellow.
These type problems usually have to do with the propagation of the flame. Its usually a question of moving the particles that the flame goes thru.
As for the replacement pilot, is the flame covering the thermopile and thermocouple? Are all the thermopile and thermocouple connections tight?
GFM
@@grayfurnaceman so they have both, thermal couple and thermal pile?
@@rickeykeeton4770 They often do.
GFM
Why does my voltage go up then drop while testing a pile?
If the thermopile is under load, its voltage drops.
GFM
Ok thanks for the info.
Be on the lookout for improper thermostats with millivolt systems ,, the compensator in a normal 24 volt "mechanical" thermostat creates resistance in the circuit , this thermostat might work with a brand new thermopile but as they weaken slightly with age you will end up with not enough current flow to open the gas valve .. the thermostat must be designed for millivolt ,, and not have a resistive compensator in the circuit,, had a gas fireplace that would work fine in the "on" position ,, but not work when in the Tstat position (not enough current due to thermostat being the wrong type) thermopile itself tested around 550 millivolts , replacing the thermopile with a new one would be a temp fix due to the new thermopile being slightly stronger when its brand new but the core fault was "thermostat wrong type"..
Yes , fully understood
You are correct. If it is not a millivolt thermostat sometimes they work and sometimes they don't. A Lot of fireplaces are set up with 24 volt thermostats.
GFM
how make thermopile in low prise please adviced me.
If you are looking for a low price on a thermocouple I would try the internet sources.
GFM
interesting vid, thanks for posting
need to connect circulator pump to burner circuit,to operate simutanous. control ra832a not correct.need relay to connect circulator to 110 v circuit.
good one, thanks...
a thermopile is numerous thermocouples in one package
jjcud Correct. They are wired in series to increase voltage.
GFM
Power is in W not mV
When the thermopile system is used, the power source is the thermopile so we don't use the same terms.
GFM
How many Amperes at 0.034 mV?
I have never measured but it will be in the low milliamps.
GFM
I have a gas fire place my stove will light manually when I flip the switch but won't light with the thermostat . pilot is working once stove manually starts and I flip the switch to thermostat it will run and shut off when it reaches set temp but will not restart when temp in house drops it's millivolt system if I disconnect the two wires put them together and start the stove flip it to thermostat will stay running separate the wires it shuts off any ideas would be great even tried new thermostat no luck thanks for your time
Are you using an electronic thermostat? Also is the thermostat a millivolt thermostat? There is a difference. Also make sure all terminals are clean and tight. Hope this helps.
GFM
triple read above my message
when t stat energizes burner
544 mil would reflect a woking valve. 250 to 300 mill would be a working valve with a load. What would be in mill volts a bad working valve
I have to disagree on your numbers. 325 or higher open circuit. 100 to 125 closed circuit. Check with the manufacturers.
GFM
It is a millivolt thermostat battery power electronic I've changed wiring everything is tight and new battery's I'm baffled worked fine last year when I restated this year when the problem started changed thermal couple about three years old never changed thermal pile stove is about 15 years old Vermont castings radiance stove thanks for your time and writing back
Be sure your flame covers the thermopile. If so change the thermopile.
GFM
grayfurnaceman This is typically what gets them in this situation, you cannot bake them into submission, They require a cool end and a hot end, not 2 hot ends,A temperature differential is what makes the dissimilar metals create the 3/4 volt or 750mv.
750mv systems are easily troubleshot with a AAA battery in a Radio Shack battery holder with alligator clip leads, or just a battery and wire taped on each end of the battery to simulate a good flame signal, a battery is more than 750mv but at this level it will not hurt a thing to put 1.5 v to a 750mv system.
Keep in mind a 750mv system often uses low voltage wiring to its stat, a tarnish or patina or moisture etc can easily disrupt this, the current flows outside the wiring and that is enough to make the stat quit operating. get the wire shiny at both ends, floor furnces did this alot, with the prices of a tcouple and tple, you are doing nobody any favors by leaving one in if already therem trust me a call back on a millivolt system is embarrassing to me but they can actually be tough if you do not think with a fine touch, like clean wires no tarnish etc, and test with a battery and replace serviceable parts like the pilot safetys
You only want the flame impinging upon the top 1/3 to 1/2 at most or risk this type of stuff.
My land lord purchased a Whirlpool nautral gas hot water heater. This was a brand new water heater that was purchased from Lowes. The plumber hooked it up and it wouldn't fire. The thermal switch was broken. So since Thursday evening I have had no hot water. Isn't there a way to force light the water heater? Why doesn't the government force Honeywell to stop making those worthless electronic gas valves.
altlandf You can thank government agencies for that. Water heaters have been changed for safety issues. There is no way to force them. Manufacturers make what passes safety regulations. GFM
This electronic valve has a major design flaw. There's nothing wrong with the old school no electronic valve. If you get the 4 flashedes on the Honeywell valve it's done. Another thing why don't plumbers have this part? Why would they not be able to get them locally? www.tylertork.com/qna/2013/gasvalve talks about all the issues with these worthless electronic valves. This is bullshit.
Thermocouple
Then I would replace the thermopile.
GFM
SUPPER
DINNER? LUNCH?
I still don't know what the hell is going on or what a thermopile is… not helpful.
Chloe Smith I guess I have never done one the mechanics of how they work. I will do one. Thanks for the thoughts.
GFM