How to Get Rid of the Smell of Mildew From a Central Air Conditioner

Insert a screwdriver into the screws of the air conditioner unit’s housing panels and unscrew them. Set the screws aside and remove the panels to expose the cooling element or cooling coils.

Shine a flashlight through one side of the coils, and then the other. If the coils are clean, you should be able to see the flashlight clearly on the other side of the unit. If the coils are dirty or caked with mold, then the light from the flashlight should be not visible. Make sure to locate the electronic components of the air conditioner and note their position, so they are not sprayed with water.

Spray foaming coil cleaner on the central air conditioner coils until they’re completely covered. If dirty, spray the condenser fan blades as well. Allow the coil cleaner to sit for the specified amount of time as indicated by the coil cleaner's directions.

Screw the garden hose into the faucet on the side of the home. Twist the faucet knob counterclockwise to turn the water on. Pull the faucet over to the central air conditioner. Spray the coils and the condenser fan blades with water until it runs out clean on the other side of the coils. Avoid spraying the electrical components with water.

Let the water drain completely from the air conditioner unit. If unable to drain, use the wet-dry vacuum to suck up the remaining water.

Replace the housing panels on the unit and screw them in with the screwdriver.

Pull the intake grille open on the inside of the home and remove the air filter. Inspect the air filter for dust or grimy buildup. If the filter is very dirty either replace it or clean it. To clean it, run warm water over both sides of the filter until the dirt is completely removed. Allow the filter to air dry before reinsertion. Close the intake grille.