I change the thermostat thingking the swith was messed up, and no luck. I have it on AUTO.
Why doesn't my fan turn off from the thermostat from the A.C?
I think what you are saying is that the fan never shuts off. If this is the case you have a bad blower relay. A blower relay is a switch with a set of contact points in it that turns the blower on and off when comanded to do so. If these points arc too many times they sometimes stick, and do not let the blower shut off, which it sounds like it did in your case. This is not a dangerous situation,as some people let their fans run all the time. You proably want to get this fixed at some point, but it is not an emergency. Hope this helps. Good Luck.
Why doesn't my fan turn off from the thermostat from the A.C?
The blower for later model central air conditioning systems is designed to run for a short while AFTER the outside unit (the condenser) has shut off. This is to prevent the refrigerant from freezing in the evaporator (the inside unit mounted on top of the furnace). As the blower continues to run, it puts heat into the evaporator which warms up the refrigerant. Otherwise, if the refrigerant were to freeze in the evaporator, the next time you turned on the air conditioner the pressure would build up in the system and you might blow out the compressor.
