Originally Posted by tevz32
Restorium, I do not hear a click, and the fan does not come on. There is no response when switching to "furnace". The AC comes on when switching to "cool" when I am plugged in to shore power
So the thermostat does work and has 12 volt to it. You eliminated a few things by reporting on the AC.
But no 'click' when you lower the temp on the thermostat into the range that would energize the heater?
I would confirm that by trying it a few times.
If there is no 'click' at all as you lower the temp while the heater switch is on then it seems like it must be the thermostat is malfunctioning. Maybe the heater 'on off' part of it. Try switching that part back and forth a few times and see if anything changes. That part wears out because it is one of the moving parts that gets used a lot.