Question AC comes on with heater when I turn heater on

[CorryG]

I have a 2020 North Trail 22RBK purchased one month ago (Jul 2022). I’m in the Pacific Northwest and tried to turn on my heater yesterday. The heater came on but so did the air conditioner. My owners manual is a generic North Trail one from 2017. Does anybody know of a setting in the thermostat that I can use to stop the AC from coming on when I turn on the heater? Thanks in advance for any help anyone can provide

 

[Ward Fuller-Rv tech.]

I've seen this happen and is often caused by the thermostat not being set to auto mode, but rather being set to low or high fan mode

 

[Dan_Frisbie]

Does your A/C have a heat pump as well?
My 15k (fwd) A/C has a heat pump and the same thermostat controls the forward A/C, the heat pump, and the furnace. The heat pump comes on first, but if it can’t handle the cold, the furnace kicks on.