A/C or Heat does not work w/thermostat set "on" or "auto".
Asked Mar 29, 2007, 05:08 AM
A/C or Heat doesn't work in "on" or "auto". Fan will not come on at the "on" position either. I changed the batteries in the thermostat. I also read somewhere to disconnect the "Y" and hold it to the "R" on the thermostat for two minutes. That will tell me if the thermostat is the problem. Still nothing worked. I checked to make sure the outlet the furnace was plugged into had power... it does. I then removed the cover from the circuit board on the central air unit. It is a Ducane, it has a Honeywell circuit board. I looked at that wiring for a little while and decided to remove the in coming hot and the "cool" wire leading to the fan. I wired those together and the fan came on. I then (by mistake) put the cool lead back in place but accidentally put it on the "continuous on" lead. The fan turned on and wouldn't turn off, can you imagine? After that I cut power and put it back the way it's supposed to be... nothing. Does this mean the circuit board is bad? Or a relay on the board? What is the next step? Replace the board? Or am I completely off base?
Thank you for any help you can give.