Step by step
This is for the outdoor condenser, the metal box outside your house, and only its outside surfaces.
- Turn the system off at the thermostat. If there’s an outdoor shutoff switch next to the unit, turn that off too.
- Clear leaves, sticks and grass clippings from around the base and off the top grille.
- Brush loose debris off the face of the fins with a soft brush, moving in the same direction as the fins.
- Rinse the fins with a garden hose on a gentle spray, not a jet setting or a pressure washer.
- Turn the system back on when you’re done.
- Trim plants back so there’s at least two feet of clear space around the unit, as the Department of Energy recommends.
Can you pressure wash an AC unit?
No. The fins on the coil are thin aluminum, and the Department of Energy notes they can bend and block airflow. A pressure washer can fold rows of them over in one pass.
Bent fins aren’t a DIY fix either. The Department of Energy says a qualified HVAC contractor can straighten them with a fin comb, and we don’t do that work ourselves.
What not to do
Keep it simple and stay on the outside of the unit:
- Don’t remove panels or reach inside the unit.
- Don’t spray water into the electrical box or wiring.
- Don’t touch refrigerant lines or connections.
- Don’t use a pressure washer or a jet nozzle.
- Don’t try to straighten fins with a screwdriver or knife.
Should you cover it in winter?
The Department of Energy says covering the outdoor unit of a central air conditioner protects it from winter weather and debris. If your system is a heat pump, don’t cover the outdoor unit, because a cover keeps the system from heating your home properly.
Not sure which you have? A heat pump heats and cools with the same outdoor unit, so if that unit runs in winter, leave it uncovered, or ask the company that installed your system.
When it isn’t a cleaning problem
If your system isn’t cooling or is freezing up, a rinse won’t fix it. The Department of Energy says a system that fails to cool your home adequately calls for a professional technician, who can check the refrigerant, test for leaks and measure airflow.
We clean the outside of outdoor units only. We don’t repair, service or diagnose A/C systems, and we don’t touch refrigerant.