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Angi How To Clean Your Window Unit Air Conditioner

Date Published: Nov. 12, 2019

Time: 45 Minutes

Sprucing up the inside of your window AC unit will help restore it to glory and remove any mildew and mold that may have accumulated inside. Even if your unit is running smoothly, it's a good idea to give it a clean once a year to make sure it's running efficiently. Check your filter once a month and clean it whenever it looks dirty.


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Tools & Materials Needed 
hand-held spray bottle
2 soft cloths
fin comb
soft-bristle brush
rubber gloves
coil cleaner (available at your local hardware store)
1Disconnect the unit from all power sources.

Unplug all power cords going into the unit. If your window unit is wired directly to your home, disconnect the unit from the fuses (or turn off the master circuit breaker). Follow the manufacturer's instruction for discharging the capacitor. A capacitor is a device that holds an extra charge to help kick-start the AC motor, so this step is critical to ensure that there is no electrical charge left in the unit before you begin cleaning.

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2Clean the outside cover.

Wipe down the outside of the window unit with a wet cloth. Be sure to get as much dust and grime off as possible so that it doesn't fall inside the unit when you open the cover.

3Remove the front cover.

Some covers can be pulled off easily with your hands. Other covers may have plastic hooks or screws that need to be removed. Place any screws or clamps in a safe place while you work.


Note: Some units also have a metal grill that needs to be removed. Use caution as you handle the grill, the metal edges can be sharp!

4Clean filter.

If your unit has a reusable filter, it needs to be cleaned. Remove the filter from the AC unit. Place the filter in a bucket (a sink or bathtub will also work) filled about halfway with warm, soapy water. Swish the filter around to wash off any dirt or buildup. If the filter is really dirty, you may need to use a soft brush to get rid of everything. Set the filter aside and allow it to dry completely before returning it to the AC unit. A wet filter will attract extra dirt and mold!

5Change filter.

If your unit has a disposable filter, change the a/c filter regularly. The U.S. department of energy suggests that filters be changed once a month during the cooling season.

6Vacuum the inside of the unit.

Use a vacuum extension to clean the bottom and sides of the unit, the back of the front cover, and the metal grill (if you have one). If there is lot of dirt, you can also use a moist rag for this step.

7Reassemble the unit.

Allow the unit to completely dry before reassembling. Plug in the window unit's power source and turn it on. Clean up any debris that may shoot out when the unit is powered on again.

8Store your unit in a dry place.

When it's time to put your AC unit away, cover it with a sheet of plastic and place it in a dry area to prevent the growth of mold and mildew.


9If you want to go the extra mile with your air conditioner.

There are a few extra steps you can take before reassembling your unit. Be gentle as you perform these steps. The coils and fan blades are delicate and easy to bend accidentally. The motor housing is also sensitive and should be avoided while cleaning.

10Clean the coils.

Put on your rubber gloves and protective goggles. Add your coil cleaning solution to your water bottle. Lightly spray the a/c coils (and only the coils) with the solution and allow it to sit for about 10-15 minutes. Then, gently pour warm water over the coils. Make sure all coil cleaner is removed.


Note: Avoid getting water on any electrical parts near the coils. Consider placing a dry rag over any electrical parts to avoid water damage.

11Clean the fan blades.

Use a soft, clean cloth to wipe off any dirt on the fan blades. Wipe gently to avoid bending the blades. A bent blade will make your AC unit even louder!

12Repair fins.

Use a fin comb to repair any dents in the fins of your coils.