Tips for Cleaning an Air Handler Unit

The air handler unit performs a vital role in your air conditioning system. This is the indoor component of the system. It conditions and circulates air throughout the house. The unit consists of a large metal box that contains a heater, evaporator, blower, air filter and humidifier. The air handler is linked to the ductwork which distributes conditioned air throughout the house and also returns it back. An air conditioning system is one of the most heavily utilized appliances in a home. This leads to frequent build-up of dirt in the system. If not cleaned regularly, it lowers the performance of your unit as well as energy efficiency. Before you clean the air handler, turn off the power to the unit to prevent an electric shock. A few tips are given below to help you clean your unit.


It is best to use the cleaners specified in your owner’s manual. This helps to ensure a good outcome and prevent any damage to the unit. If no specific cleaners are recommended in the manual, purchase a general air conditioning cleaning solution from a home improvement store. Obtain one that includes antimicrobial agents to kill bacteria and fungi that often thrive in the unit.

De-Assemble the Unit

To effectively clean your unit, it is best to open and remove the individual parts. Remove the screws from the front access panel and place them in a safe area. Carefully lift out the fan or blower, squirrel cage and coils. Place these where you can comfortably clean them. Use a high efficiency particulate air (HEPA) vacuum to remove dirt and bacteria stuck on the inside of the unit. This type of vacuum prevents bacteria from being dispersed into the air. Dampen a cloth with an appropriate cleaning solution and use to wipe the inside and outside of the casing.


This is a common problem in air handler units. It usually develops around the coils and condensation lines. It is best to clean the coils out in the yard. A lot of water will splash around which creates more work for you if you clean in a confined area. Use a soft scrub brush and appropriate cleaning solution to clear dirt from the coils. The coils become white when cleaned. Rinse with your garden hose. Wipe excess water with a soft cloth and allow the coils to air-dry for about 1 hour before you reinstall. Drain the condensation lines then flush with algaecide or bleach to kill and remove the algae.

Rust Removal

With time, the metal box may develop some rust because of exposure to moisture. For mild cases, use a wire brush to scrape off the rust. Pour a little mineral oil onto a soft cloth and wipe the rusted areas. Add some more oil and allow about 15 minutes for it to clear the rust. It softens the rust and makes it easier to remove. You can then wipe the box with a clean cloth. Use a rust remover for severe cases of rust. Apply it over the rusted areas and wait for the stipulated time before you wipe the box clean. It is best to wear gloves when you work with rust remover as it may contain acid.