I have a new construction home with a gas fireplace (Copreci VCS-ECOMOD) that won't stay on when lit. If I leave the pilot on, the pilot is stable and stays lit indefinitely. Once I light the fireplace, the fireplace will come on and run for about 5-10 minutes then shut off. When this happens, the pilot also shuts off. After 3-5 seconds the pilot will come back on, and then I can light fireplace again. After a few cycles of this, I get a double beep, which looking at the manual is telling me there is unstable pilot. The fireplace is turned on manually through a control panel or via a simple remote. The fireplace has only a thermocouple (no thermopile). Visually, the flame touching the thermacouple when only pilot is lit, or when fireplace is lit looks blue and healthy and largely covering the thermacoupler.

Trouble shooting steps I've taken so far:

  1. Cleaned out the holes use air compressor where flames come out, including at igniter and thermocouple.
  2. Used sand paper to clean the thermocouple thoroughly.
  3. Used a voltmeter to measure a healthy 18mA from the thermocouple.
  4. Ensured there are new batteries (although not needed) in the power backup box.
  5. Adjusted flame so that it is blue coming out with yellow tips - does not have the "soot" appearance.

Any help of what to try next would be highly appreciated!

  • 1
    The thermocouple could still be unstable, not delivering consistent voltage over time. You might try measuring the voltage over a few minutes while you're applying heat to the thermo. The problem could also be in the valve itself. Because the pilot stays lit indefinitely I suspect the problem is in the valve. What make and model?
    – HoneyDo
    Dec 24, 2020 at 20:56
  • Its a Copreci VCS-ECOMOD. Before I replace the valve, I tried rotating the pilot a few degrees to get the flame to align better on top of the thermocouple- when the fireplace was lit, the pilot flame didn't exactly align over the thermocouple. So far, rotating the pilot a few degrees seems to have resolved the issue. Fireplace has been stable for a few hours now.
    – cbdoc
    Dec 24, 2020 at 23:36
  • 1
    Is the house new enough that the fireplace may still be covered by manufacturer's/installer's warranty? If so, I'd contact the installer before messing with it. They may cover everything under warranty unless you've touched, adjusted, replaced something, in which case they may claim that the problem is your fault.
    – FreeMan
    Dec 24, 2020 at 23:45

2 Answers 2


Looks like I had to rotate the pilot flame a few degrees to get it to better align with the thermocouple, especially when the fireplace was lit. This seems to have resolved the issue.


I'd start by replacing the thermocouple. They are cheap and if it doesn't solve the problem you just have a spare kicking around.

If it doesn't fix the problem then I'd replace the gas valve. I had a honey well gas valve which I believe has an internal spring mechanism - when the ambient temperature reached certain temperatures the spring would not work properly and the gas value would malfunction.

It took years to work out the problem eventually the gas valve completely failed and once replaced everything worked properly. Previously to that techs replaced air sensors, flame rollover sensors, etc I don't know for sure that something didn't contribute but since the problem was intermittent it was difficult to track down and it hasn't been a problem for at least 5 years now.

Good luck !

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.