The furnace only blows from the floor vents & it's propane powered by 12volt from the batteries. Like most rvs the floor vents aren't closable due to too much heat build up if closed. If you had your thermostat set on "electric heat" that comes from the roof heat pumps & blows through ceiling vents, but once the inside temp drops 4-5 degrees below the set temperature the furnace fires up til it reaches the thermostat setting then the heat pump will start again. The heat pump will only work adequately until the outside temps reach about 40 degrees then they start blowing cold air & your furnace will start kicking on. Your coach is not possessed, but actually working as it should.
Danny & Linda
Sold our '13 Thor Redwood 36 FB
Currently RV & truckless