Clean Your Outdoor AC or Heat Pump Unit Once a Year

The Problem

The outdoor condenser of an AC or heat pump pulls air through its coils all season, and it slowly packs with leaves, grass clippings, and dirt. A clogged coil can't shed heat, so the system runs longer, costs more to operate, and wears out sooner. A quick cleaning once or twice a year — before the cooling season — keeps it breathing.

The Technique

1. Cut the power at the breaker. Many units also have a separate disconnect or breaker box on the wall right next to them — shut that off too.
2. Remove the screws or bolts holding the top grille down (usually about four).
3. Lift the grille up and out. The fan is often bolted to it, so lift gently and set it aside without straining the wires.
4. Vacuum the leaves and debris out of the inside with a shop vac.
5. Spray the coils from the inside out with a coil cleaner or basic all-purpose cleaner. Let it sit a couple of minutes.
6. Rinse the cleaner off with a hose, again working from the inside out, so you push the gunk back out the way it came in.
7. Reassemble — set the grille and fan back, refasten the screws, and restore power.