Okay with Hurricane Ike blowing through Pittsburgh, we had blackouts followed by a brown out, after the power was fully retsored my Ac will not turn off, even if i turn it off from the thermostat, or raise the setting to higher than what it is, i can hear the themostat click but nothing. I bought a new thermostat and i still get no results, The only way for me to turn the furnace/cooling unit off is by the circuit breaker, and when i turn the breaker back on, it turns Back on
Sounds like an issue with the furn or AC...possibly electrical due to the storm. I'd consider having an HVAC tech look at it, and check with your home owners insurance and see if it may be covered due to the storm.
Just because you can, doesn't always mean you should