The A/C in my house won't stop running. I changed out the thermostat but I'm still having the same problem.

Question

The only way I can stop it is by turning the breaker off.

Answer 1

There could be several problems, shorted control wires, relay stuck in outdoor unit, timing board in furnace bad. If the outdoor unit runs without the indoor unit operating, you could do serious damage to the system. Time to call for service.

Answer 2

that is not something to take lightly since breakers can cause fires. i would call a professional asap. or ask someone who has experience to take a look at it.

Answer 3

The blower relay contacts are stuck if the blower will not shut off or the contactor is stuck if the condenser will not shut off.Replace the relay or contactor.

Answer 4

Smack the fan relay in the air handler with the end of a s***w driver not too hard now. If it stops you found the problem and it might not hang up again for a while.