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How to clean an air conditioner and keep it running like new

Air conditioner unit on wall
Air conditioner unit on wall (Image credit: Shutterstock)

Many households are blasting their air conditioners right now, to beat the heat and keep cool this summer. But like most things around the home, even air conditioners could do with a little TLC. Knowing how to clean an air conditioner ensures it works efficiently, and will also improve good air quality.  

This is often the case when the air filters inside the unit start to clog up with dust, or the unit collects moisture over time. If you don’t learn how to clean an air conditioner properly, this makes the unit work harder to move the air, as well as cool a room effectively. 

What’s more, regular cleaning equates to lower running costs, saving you money on energy bills, and can also extend its lifespan. So, if you want to remain cool during those hot months, here’s how to clean an air conditioner and beat the heat.

If you're in the market for a new unit, be sure to check out our guide to the best smart air conditioners, what to look for when buying an air conditioner, and the best air conditioner deals.

How to clean an air conditioner

1. Remove the indoor unit dust filters

Woman opening up an air conditioner

Woman opening up an air conditioner (Image credit: Shutterstock)

Before you attempt to clean your air conditioner, always turn off the power and  remove its power supply for safety. It’s also essential to read your instruction manual that came with the unit. This will explain in detail how to access and clean the filters and any other user-maintainable parts. Next, open the plastic cover of the indoor unit and remove the filter (or filters if there are more than one). Usually, the filter is located at the front of the unit, but check your manual if in doubt. 

2. Clean the filter 

Removing an air conditioner filter

(Image credit: Shutterstock)

Take the filters outdoors to shake them off before removing dust with a brush or a microfibre cloth. You can also use a vacuum cleaner, using the dusting brush head attachment. To remove stubborn grime, rinse with lukewarm water and dish soap, and allow the filter to dry completely before putting it back into the unit.  

3. Clear the coils and condenser

Man cleaning air conditioner

Man cleaning air conditioner (Image credit: Shutterstock)

Most air conditioner units have evaporator coils inside the unit, and condenser coils at the back, which are outside. Using a screwdriver, remove the top and side panels to reach the condenser coils. Next, take a soft brush or a special coil brush to gently remove dirt. Be sure to inspect any coil fins for damage, and carefully straighten out any bent ones with a fin comb like this Air Conditioner Condenser Fin Comb ($8, Amazon (opens in new tab)). After the outside of the coil is done, you can use one of the best vacuum cleaners for the inside.  

4. Ensure all parts are dry before replacing

Turning on an air conditioner

Turning on an air conditioner (Image credit: Shutterstock)

Next, wipe the outside of the unit clean using dish soap and lukewarm water. Ensure all removable parts are completely dry before putting back the cover. Then you can put the power back on, and set it to your preferred cooling mode . 

If done correctly, you should notice a better performance and cooling experience. 

How often should you clean an air conditioner? 

Vacuum cleaning an air conditioner unit

Vacuum cleaning an air conditioner unit (Image credit: Shutterstock)

Most manufacturers recommend that you should clean the dust filters every few weeks, but this really depends on how often you use your air conditioner. It’s also recommended to clean or replace the filters once a month while it's being used. However, if you only turn on your air conditioner occasionally, every two months would be sufficient.  

If in doubt however, you can call in a professional to service your air conditioning unit and maintenance needs. 

Cynthia Lawrence
Cynthia Lawrence

Cynthia Lawrence specialises in Homes ecommerce, covering all things homes and garden-related. She has a wealth of editorial experience testing the latest, ‘must-have’ home appliances, writing buying guides and the handy ‘how to’ features. 


Her work has been published in various titles including, T3, Top Ten Reviews, Ideal Home, Real Homes, Livingetc. and House Beautiful, amongst many.


With a rather unhealthy obsession for all things homes and interiors, she also has an interior design blog for style inspiration and savvy storage solutions (get rid of that clutter!). When she’s not testing cool products, she’ll be searching online for more decor ideas to spruce up her family home or looking for a great bargain!