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:
- Cleaned out the holes use air compressor where flames come out, including at igniter and thermocouple.
- Used sand paper to clean the thermocouple thoroughly.
- Used a voltmeter to measure a healthy 18mA from the thermocouple.
- Ensured there are new batteries (although not needed) in the power backup box.
- 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!