2nd Floor Air System Sometimes Works Sometimes Not
We just purchased this home, figures on walk through inspection the air worked fine. What we are seeing is that at night the unit works fine and even sometimes, rarely, the unit works during the day. It is an upstairs unit (split) and the compressor is out back. I have sprayed the compressor fins (sorry but I am no air technician nor do I know the terms) with water hose and pressure washer to clean them out. The Fan works fine and all looks okay. When the system works the thermostat is calling for air conditioning and the air is coming from the vents cool and forceful enough to tell it is blowing. The air return, which is in the ceiling, is holding pressure on the filter which is not that dirty. When the system is not working the pressure is still held on the filter and you can hear the motor working above the ceil same as when it is working. The difference is that the upstairs progressively gets hotter and by feeling up around the vents there is NO cool air coming out at all in fact sometimes the air you feel is HOT air instead. It is also as if the blower has stopped working. I don't understand this working and not working and it seems to me that if it was the coolant that it wouldn't cool at any time. Any suggestions before I call a professional in to evaluate the problem?
Answer:
Since the filter is clean, and the blower works, It sounds like the unit may be low on freon, or has a defective or blocked metering device. Time to call a professional.... Is your t-stat fan selecter set to "on"? If so the blower/indoor fan will run continously, but the compressor will cycle as needed by the t-stat. When t-stat isn't calling for cooling, the fan just circulates air which may make it feel "warm" Jay