Forum Discussion

Explorer

Nov 16, 2015

A/C Turns on when I turn on the heater

When I turn on my heater the A/C also turn on.
Is a gas furnace. So I have to turn the A/C beaker down.
If I only use the A/C it work fine.
Any ideas.
I think my digital thermostat is damaged ?

13 Replies

Tbucket
Explorer
Nov 16, 2015
I don't have auto mode. Only 3 functions.

Fan
Cool
Furnace
jetcare
Explorer
Nov 16, 2015
If you have a newer style Dometic Thermostat, push the Mode button so that the FAN position is illuminated. Use the +/- buttons to move the fan to AUTO. Right now, you have it in the Low or High position.
Snowman9000
Explorer
Nov 16, 2015
It's probably the AC fan only, not the compressor. I had the same issue. It was the setting for the fan. It was a little confusing if I recall. But you need to change it to Auto. IMO it is poor logic by the thermostat designer.