Hello all,

I have a classic A/C and heating system with an inside down-flow fan unit, furnace, and cooling coils, and an outside compressor/condenser unit. Just this week, I noticed that the compressor/condenser unit continues to run like it normally would when the A/C is on (i.e. the compressor and the condenser fan are running), but it runs non-stop, even when I have cooling turned off on the thermostat. When I pull the 110V plug on the inside fan unit, the compressor and condenser shut off, but as soon as I plug it in, they come back on.

I have seen this happen before some years ago in a different house after a thunderstorm and we had a recent thunderstorm here, but I can't remember what the problem was as how to fix it. Any ideas on what this might be? I thought it might be a relay on the inside fan unit but I pulled the only relay I could find without any luck -- turns out that relay is for the inside fan blower motor. Maybe I have a stuck relay on the outside unit?

Probably doesn't matter, but the system is a Rheem RAFD-036JAS.

Thank you in advance!

Matt

Not sure, are you saying you have to turn the 110 off to the furnace, or the 220 off to the ac to get it to shut off?

Sorry for the confusion. I can shut it off by pulling the 110 at the furnace or the 220 on the compressor/condenser. However, I have since discovered it is my thermostat. Installed a new LuxPro this winter and it worked fine until we had to turn on the A/C this month. Not happy with that product.

Thanks for the reply.

Matt