Cooling · 4 min read
Why Is My Air Conditioner Running but Not Cooling?
The unit hums along and the vents blow, but the house stays warm. These are the usual causes, in the order we check them.
When an air conditioner runs without cooling, airflow is the first thing to examine. A loaded filter, a blocked return or a dirty indoor coil restricts air across the coil, and a restricted coil cannot move heat out of your home no matter how long the system runs.
The second area is the refrigerant circuit. Symptoms such as ice on the line set, a coil that frosts over or long run times with barely cool supply air point to a circuit issue that needs proper testing — not a top-up guess.
Third are electrical and control faults. A failing capacitor, a contactor that is not pulling in, or a thermostat calling incorrectly can all leave the indoor blower running while the outdoor unit does little or nothing useful.
Finally, consider the envelope. On the hottest afternoons a correctly sized system will run long cycles, and a home with significant heat gain can feel warm even while the equipment performs to spec. Diagnosis separates an equipment fault from a comfort and sizing issue, and the fix is different in each case.
Questions about your own system? Call Thermetix Mechanical Inc. at 647-227-1214 or request service.