We have a Frederich SM18J30 18000 BTU through the wall AC on the first floor of our small Cape. It has been a work horse for 20 years without any big problems. Yesterday morning I turned the power off (was running all night) and the compressor wouldn't shut off. So now the compressor just stays on and the thermostat has no effect and I have to pull the plug to turn it off. I did some googling and it seems like it is probably a broken relay which makes sense. I am leaning towards replacing it because of its age but it still works well. Not sure if I can find someone to repair it. Finding parts might be a problem. I think most AC repair places around here deal with central air only. Should I break down and get a new one ($1600 is what I am seeing for a similar 18000 btu that fits this opening) or should I try and find someone to repair it? Thanks in advance.