An outside unit that hums while the fan stays still is the call we get most in July in Sumter, SC, 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.
When the heat goes out, see Furnace Repair.
When to Call for AC Repair in Sumter
The sooner you notice these red flags, the easier and cheaper the fix. Keep an eye out for the following clues:
- Ice on the refrigerant lines or a frozen indoor coil
- Puddles near the air handler or water stains on the ceiling beneath it
- The system short-cycling every few minutes without cooling the house
- Warm or room-temperature air blowing when the thermostat calls for cooling
- Cooling bills climbing while the house stays sticky and warm
- The outdoor unit humming or clicking but the fan not spinning
- A hiss or gurgle from the lines, a common sign of leaking refrigerant
- Breaker trips or a burning odor at startup
Act Before It Gets Worse
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 (803) 887-7786 at the first sign of trouble.
