Last summer my air conditioner worked fine but now it is not. The inside fan works and the outside unit seems to be running. I called a technician who is coming Monday, but he had me do some basic troubleshooting first. He had me check the temperature of the big copper pipe running from the outside unit into the house and it was not cold as it should have been. Then he had me switch into heat mode and the big copper pipe outside did get hot as it should have. Supposedly the pipe getting hot in heat mode is evidence that the compressor‘s working and that I have freon. So what could be the problem?
When running as an a/c, check to see if the air on top of the condensor feels at all warm, this will also let you know if the compressor is running. And then feel both refrigerant lines to see if there is any temperature change from either as its running compared to what they feel like when its not running. These checks will at least tell you whether or not the compressor is pumping and if it is, then its probably low on freon. Other wise, the compressor is not running, in either case, the tech will have to do all diagnostics
from your question i'm assuming you have a heat pump, right? how accurate were your measurements and what was the outside temp? are you asking the system to cool down in a situation where the unit is not exchanging heat? it could be a refrigerant leak or a pressure switch has tripped for some reason. could be a faulty circuit board. it could be a lot of things. i don't trust your measurements on the liquid line. remember, outside air temp has a huge part in determining pressures and temps of lines. it could be a lot of things. let's hope the reversing valve isnt shot, EXPENSIVE as in new unit expensive. i would give the electric components a once over then hook up my gauges and check the pressures and go from there. IF you are low on refrigerant, ask the tech to find the leak and fix it. i would start at the indoor coil with my sniffer. GL with it! jim
