Troubleshooting AC Won't Shut Off

Updated 04/25/2024 | Published 04/18/2024

Question:

Currently have a Dometic thermostat the fan runs on the air conditioner when I turn the air furnace on, it runs continuously even when the furnace reaches set point and turns off. Can you provide info on if it is simply a termostat replacement or ? The only way I can get the air conditioner to stop running is to turn the breaker off.

asked by: Tom

Expert Reply:

It is possible it is the thermostat but it could also be faulty wiring. Go ahead and check to make sure your wiring connections are in good shape and also that your ground connections are secure. I'm not sure what your exact setup is but if you have warm air from the furnace getting to the temp sensor for the AC it could be causing it to run continuously although I really wouldn't expect both to run at the same time. If it is neither of these, thermostat replacement with the # DMC79FR is probably a good idea.

expert reply by: Robin H