question about 2011 Gulfstream thermostat

[Bessie7881]

Hello. in my 2011 Gulfstream, do not understand how to set temp and keep place warm without having to turn it off and on manually.I have gone over manuals but nothing in there. The settings are : Under "System" , cool. fan, off heat, and under "Fan" Auto, fan and on offering low and high

[enblethen]

Could be a bad battery in the thermostat, if it has one.

[nickthehunter]

What is preventing you from setting it to some desired temperature (say 70°) and leaving it there?
Does it not shut off and just keep going up and up and up?
If yes, does just the fan keep running --or-- does the fan and the burner (defined as - heat output) keep running?
Will the burner shut off eventually (even though the fan only may keep blowing air)?
Basically, in most instances, the "System" should be set to Heat and the "Fan" should be set to Auto.
You should also check the wiring at the thermostat; a stray wire could be touching an adjoining wiring lug. That's the easy problem to fix, it gets more complicated beyond that.

[enblethen]

Make and model of thermostat?