Before you call
Filter, Coil, and Condensate Drain: Three Checks Before You Call
Most no-cool calls in summer are a spent filter, a packed outdoor coil, or a drain that will not empty.
Before you book independent AC repair, check three things. They are not a substitute for a failed capacitor. They are the reason a lot of trucks roll for nothing.
The filter
Find the slot, not a guess in the ceiling. If the filter is collapsed, gray, or you cannot see light through it, replace it with the size printed on the old one. Run the system for thirty minutes. If the house starts to catch up, you found it.
A higher MERV rating than the system was built for can choke an older blower. Match the filter to the equipment, not to an ad.
The outdoor coil
Kill power at the disconnect before you put your hands near the fan. If the fins are matted with dirt, a gentle rinse from the inside out is enough. Bent fins and a pressure washer are how people turn a dirty coil into a damaged one.
The drain
A full pan, a wet ceiling, or a float switch that has shut the system off is a drain problem until proven otherwise. A wet/dry vacuum on the outside end of the line clears a lot of them. If the pan has been overflowing onto a heat exchanger or electrical parts, stop and call.
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