How to Clean a Room Air Conditioner

Cleaning procedure

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Photo 1: Comb out the mats

Match the correct end of the fin comb to the fin spacing on your coils. Then insert the comb and pull up to straighten the fins. Wear leather gloves to prevent nasty cuts.

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Fin comb

Fin combs are available for most common air conditioners.

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Photo 2: Clean out the crud

Suck up all the spider webs, leaves, dust and dirt before you spray the coils.

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Photo 3: Apply a foam cleaner

Shoot the spray over the entire surface of both coils and let the foam do the work for you. If the buildup is heavy, brush in the direction of the fins with a nylon-bristle brush.

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Photo 4: Service the fan motor

Pop off the plastic or rubber caps on the motor's oiling ports. Then squeeze a few drops into each port and recap.

Most people assume warm air from their A/C unit means it’s low on refrigerant. That’s not always the cause. Many times, window and through-the-wall A/C units can’t blow cold air because the evaporator and condenser coils or cooling fins are clogged. Professional cleaning costs over $100. But you can do the entire job yourself in about an hour with a few dollars in supplies. If cleaning doesn’t do the trick, you can always call in a pro (or buy a newer, more efficient unit). Here’s how to clean your A/C unit.

First remove the plastic filter holder/trim panel. It usually snaps off. Then remove it from the window or slide it out of the wall (get help—it’s heavy).

If you’re working on a window unit, remove the mounting frame and the case. The case screws are usually located along the bottom edge. Note the location of any odd-length screws since they have to go back in the same spots upon reassembly.

Then straighten the bent cooling fins with a fin comb (Photo 1). The Frigidaire fin comb kit shown here is cheap and fits most brands of air conditioners.