Home Central Air Conditioner does not turn shut off?

Question

This is strange. Everything turns on when I use the thermostat (luxpro programable) to set cool auto or on. The problem is, it does not turn off. When I use the switch on the thermostat to the off position, the fan in the house turns off, but the fan from the outside does not. It continues to run coolant thru. I have to go to the furnance and turn off the main power switch. Any ideas? is it a thermostat issue, or did a wire corrode and pop loose.

Answer 1

Sounds like the contactor in your condenser has welded shut. Call in an HVAC company to repair.

Answer 2

If you just replaced this thermostat, I would suggest it was wired incorrectly. Your thermostat may also be defective. If you take all the wires loose from the stat, nothing should run. If it still runs, you probably have a bad wire from the furnace to the stat. Replace the wires. Good luck.