Air conditioner doesn’t cool?
July 1, 2009
Air conditioner doesn’t cool
A central air conditioner that runs but doesn’t cool may just need to be cleaned. Plan to do this on a relatively warm day. Follow the instructions in your owner’s manual.
- Before you begin, turn off the power to the unit. There is normally a shut-off or disconnect panel on the house wall next to the outdoor compressor. Otherwise, shut off the air conditioner’s 240-volt circuit at the main electrical panel.
- Rake leaves and debris away from the outdoor condenser.
- Remove any protective grille or cover from the condenser’s fins.
- Use a soft brush to clean dirt and debris from the fins, and then vacuum them with a brush attachment (be careful not to damage the fins).
- Unscrew and lift the top grille off the unit, if possible. If the fan is attached to the grille, be careful not to pull any wires loose.
- From inside the unit, hose down the fins (protect the wiring and motor with plastic sheeting). If your owner’s manual calls for lubricating the motor, do that now—but don’t overlubricate.
- Reassemble the unit.
- To test it, turn the power on and set the thermostat to turn the unit on. Let it run for a few minutes, and then feel the two pipes that connect to the condenser unit (slide any insulation back). One should feel warm, the other cool. Otherwise, call an air-conditioning technician—the refrigerant may need to be recharged.
Important note: Avoid straining an air conditioner’s compressor by waiting at least five minutes between turning it off at the thermostat and turning it back on.






