Dometic thermostat furnace issue

[TrailCreek]

I've seen a few topics that almost covered this issue, but nothing with a solution to my problem. The t-stat will run the furnace until it doesn't. What I mean is that it randomly fails to start the furnace when the temp falls. I turn it off and back on and it starts working again. It seems like a thermostat problem but with so much technology running two heat pumps, one AC and a furnace, it could be any of the above or the controller. Anyone have this issue and fixed it?

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[TrailCreek]

DOMETIC 3314082.000 BLACK COMFORT CONTROL CENTER II DIGITAL RV THERMOSTAT

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[jerryjay11]

Be aware when the RV furnace has an issue with igniting or staying lit it will shut down on safety. To reset it you need to turn the T-stat or power switch off then on again. So, I'd be alert to that as well.

 

[centerline]

the Tstat on the wall may not be the issue.... it sounds as if the furnace is going into "lockout" mode, which could be a failed over-temp thermistor within the furnace housing.... you can borrow a wall T-stat and connect it in place of the existing unit and see if there are any changes, but the wall thermostat is really only a controller, an automatic on/off switch for the circuit board on the furnace.... the circuit board does all the signaling that the furnace needs to run properly, and if a thermistor fails, it will shut down in the mode that you are describing.... there are other reasons as well, which the most common is if there is air in the propane line, but this will work out if you keep resetting it to run, until the air is displaced by propane..... it can take several attempts, but after 5 tries, I would be looking for another fault elsewhere....