My Dometic 15K has brain fade

Sure sounds like a bad stat

What I have observed on my RV is the temperature may be at the set point on a thermometer sitting on a counter top but different at the single zone thermostat. From what I can see the thermostat is picking up the heat soak from behind the cabinet. It reads 89 degrees when at the countertop and most of the RV is at the set point. It never matches up until the sun goes down.

1: Does stat run both AC and Furnace? And 2:is it "electronic".

if it is electronic then it needs power.. Normally most Heat/Cool stats get poer from the "heat" side (Furnace) and run on a rechargeable battery during Heating cycles ... That battery may need replacement.

Some use replicable batteries. and again replacement may be needed.

I do not know about yours

Mine Factory the A/C itself (one of 'em) operated the furnace and drew house power.. When that A/C went bad I the new one did not have the ability to control the furnace. So we taped off those leads and I put a mechanical T-Stat on the wall. It did not need batteries.. and since it was "Mercury Free" it did not even need to be level.

wa8yxm wrote:
1: Does stat run both AC and Furnace? And 2:is it "electronic".

if it is electronic then it needs power.. Normally most Heat/Cool stats get poer from the "heat" side (Furnace) and run on a rechargeable battery during Heating cycles ... That battery may need replacement.

Some use replicable batteries. and again replacement may be needed.

I do not know about yours

Mine Factory the A/C itself (one of 'em) operated the furnace and drew house power.. When that A/C went bad I the new one did not have the ability to control the furnace. So we taped off those leads and I put a mechanical T-Stat on the wall. It did not need batteries.. and since it was "Mercury Free" it did not even need to be level.

Per my post, the stat is a Dometic single zone which is totally electronic. It runs both AC and Furnace and is working with both, but on the AC side it will not turn off once activated. No batteries in this system. Runs off house 12v. Thanks.