# Replaced Thermopile - Still Have Thermopile Issue (Now What)?



## PolishPete (Aug 19, 2013)

I've got a roughly 8 year old Whirpool Waterheater with your common Honeywell gas valve.

Pilot wouldn't stay on and was getting the 2 blink LED notification for low thermopile voltage.

Replaced the thermopile but still getting the same issue (pilot wont hold, gets the low thermopile voltage issue).

Is there anything else I should be cleaning or changing down there that could help resolve this?

Appreciate any help.


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## Chris616 (Dec 31, 2019)

Gene Haynes has a really informative website for help with water heater (and other) issues:
http://waterheatertimer.org/troubleshoot/troubleshoot-water-heater-thermopile.html

Chris


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## user_12345a (Nov 23, 2014)

Could be a dirty pilot orifice.

it's not a good idea to change parts before diagnosing the problem. the error code doesn't tell you what part to change.


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## PolishPete (Aug 19, 2013)

Chris616 said:


> Gene Haynes has a really informative website for help with water heater (and other) issues:
> http://waterheatertimer.org/troubleshoot/troubleshoot-water-heater-thermopile.html
> 
> Thanks, I will look through it.
> ...





user_12345a said:


> Could be a dirty pilot orifice.
> 
> it's not a good idea to change parts before diagnosing the problem. the error code doesn't tell you what part to change.


I agree. Being a semi-handy DIY homeowner without specific knowledge of it, I was hoping the LED marked the problem, and the googling bringing me to replace the thermopile would do the trick (without somehow testing the specific part before replacing it).


It any case, I replaced just the thermopile, but still getting the same issue. (Pilot light wont stay on, getting the 2-LED blink error on the Honeywell gas valve unit).

So I replaced the whole assembly (gas tube/igniter/thermopile) thinking maybe the ignitor or something was dirty/worn. Relatively cheap on Amazon for the part so figured replacing the whole assembly was worth it.

However...still the same problem!! The pilot light wont stay on. You ignite the pilot, get the 1-LED per second normal signal, I hear a click inside the Honeywell gas vale, 1-LED persists for a few seconds so it looks like everything is good, then goes to the 2-LED error for a few blinks, then turns off completely.

Any further ideas on how to diagnose, or what the problem could be?

(I have 2 water heaters, so we still have hot water, but if my wife and child take a shower then we're out, so would like to get the 2nd one going.)

Thanks again for any help.


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## PolishPete (Aug 19, 2013)

Also forgot to mention, the new "kit" included a brass screw on tip for the gas pilot tube. The old one taken out of the water heater had the gas pilot tube "tinned" like in this photo. Otherwise all of the parts were identical. Wonder if that is a problem??

Picture below an example of the tinned connector vs. the new "kit" that I purchased to replace the whole assembly.


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## surferdude2 (Nov 21, 2019)

Check the high temp cutoff switch located behind the removable burner access plate. It screws into the tank and has two wires coming from to the control board. There may be a manual reset button on the center of it that you can press to reset it.


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## surferdude2 (Nov 21, 2019)

PolishPete said:


> Also forgot to mention, the new "kit" included a brass screw on tip for the gas pilot tube. The old one taken out of the water heater had the gas pilot tube "tinned" like in this photo. Otherwise all of the parts were identical. Wonder if that is a problem??
> 
> Picture below an example of the tinned connector vs. the new "kit" that I purchased to replace the whole assembly.


You are comparing the wrong items. The tinned connector is on the thermopile electrical connector fitting and the brass compression nut is on the pilot gas tubing.

They provided a new compression nut since you may have to cut the new tubing to size and the old nut can't be removed for reuse. Once you tighten a compression fitting, the ferrule compresses to squeeze onto the tubing permanently.


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## PolishPete (Aug 19, 2013)

Thanks all for the help so far. Here's where I'm at (what I've tested), but yet still not getting it to light.

- The thermopile assembly (thermopile/igniter/gas tube) was replaced with new.
- Thermal cutoff switch has continuity
- Thermopile tests to 540 millivolt (I'm reading that a new one should be 600+, but anyway also reading that at about 250 +/- the solenoid should hold on its own for the pilot to stay lit)
- There is spark

I basically removed the burner assembly and hooked it all back up outside of the water heater. I have spark, and gas flow. While I hold down the pilot knob I get the pilot to light. The thermopile is giving good millivolts, but anytime I let off holding the pilot knob, the pilot light goes out. The solenoid wont hold on its own.

With the spark, thermopile, gas flow, and cut off switch all testing OK with a multimeter or visually seeing its working, but the solenoid not holding thus it not really lighting, I'm thinking the actual gas valve assembly has to be bad.

Any way to test that or just replace it? I guess I don't really have any other parts to replace or that need replacing other than that as everything else seems to be good.

Appreciate any input anyone has on what my next steps should be.

Thanks again!


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## user_12345a (Nov 23, 2014)

It does sound like the gas valve is bad.


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## surferdude2 (Nov 21, 2019)

Yes, I think your gas valve has failed. If you measured >350 MV on the red and black lines that plug into the thermostat and the limit switch measued continuity (< 1 ohm) that says it all. Remove the thermostat cover (screws are in the bottom out of sight) and double check all the connections but it's doubtful there is anything you can fix without a new valve.


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## PolishPete (Aug 19, 2013)

Thank you for the tips folks.

I've ordered a new valve. Will report back that that was the solution (hopefully).


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