An outside unit that hums while the fan stays still is the call we get most in July in Philadelphia, PA, and the cause is usually a failed run capacitor. That inexpensive component starts the compressor and fan, fades for years without complaint, and then quits under peak load. It is far from the only suspect, though. Contactors pit and stop passing clean power, condenser fan bearings dry out, small refrigerant leaks drain away cooling capacity, and evaporator coils ice over when a clogged filter strangles airflow.
Heating trouble instead? See Furnace Repair.
Warning Signs for AC Repair
Spotting the early warning signs lets you act before the problem gets expensive. Keep an eye out for the following clues:
- A burning smell or repeated breaker trips when the AC starts
- Ice on the refrigerant lines or a frozen indoor coil
- The system short-cycling every few minutes without cooling the house
- Clicking or humming outside with no fan movement
- Hissing or bubbling sounds that suggest a refrigerant leak
- Water dripping from the indoor unit or showing up on the ceiling below
- Room-temperature air from the registers even though the AC is running
- Cooling bills climbing while the house stays sticky and warm
Early Action Saves Money
A failing capacitor, clogged condensate drain, or dirty flame sensor rarely fixes itself and usually gets more expensive to address the longer it runs. Call (215) 261-4753 at the first sign of trouble.
