What we did
In August, a malfunctioning air conditioning system brought us out to a home in Nicholasville. Late summer in central Kentucky is not the time anyone wants to be without cooling, so we started by inspecting the system to see what was going on.
During the inspection, we found that the suction was very low. We added one pound of refrigerant, and the pressures rose in response. We also tested the expansion valve, which did not respond to the test. Those readings are an important part of the picture, because they help show how the system is behaving and where attention is needed.
Diagnosing an air conditioner means looking at more than one reading. Suction pressure, the response to added refrigerant, and the behavior of the expansion valve all tell part of the story. The expansion valve controls how refrigerant flows into the indoor coil, so how it responds to testing matters for how the whole system performs. For Kentucky homeowners dealing with an AC that is not keeping up in the summer heat, a methodical diagnosis like this is the starting point for deciding what comes next. Guessing at the problem tends to cost more in the end than measuring it.
