Furnace Suddenly Turned On

[SPSchaller]

2024 Primetime LaCrosse TT - My furnace suddenly turned on about 2 AM last night. It's early May in central Florida and about 75 degrees in the trailer with some windows open. The thermostat (Furrion single-zone) did not appear to be on. I pressed the thermostat ON button and the roof AC immediately kicked on. I cycled the thermostat through all the modes with no immediate affect, then turned it off. About 5 minutes later, the furnace shut down and remained off the rest of the night.
As the primary switch for the heating and cooling systems appears to be the thermostat, I was wondering if mine is failing or if something else is going on. A Furrion replacement is about $75, wasted if its something else.
Looking for ideas, suggestions...
Thanks!
Scott

 

[Gary RV_Wizard]

The furnace always has 12v power present; the thermostat merely signals whether there is a demand for heat or not by putting +12v on a signal wire to the furnace controller. It's conceivable some other wire shorted to the heat demand signal wire and the furnace simply reacted. But it's also conceivable that the furnace itself erroneously triggered the heat cycle. By the way, what make & model of furnace is it?

 

[Kirk]

I would start by downloading the manual for the thermostat that you have from this site.