I recently purchased a Northwood 2011 Fox Mountain 245 rks. Really like the unit. When I turn on the heater it fires up and heats well. After temps rise and the unit shuts off it does not come back on. I can turn heater off and then back on and it will fire up again and then not come on. I suspect the thermostat but I’m not at all sure. Any suggestions? Thank you very much. Getting cold in Montana.