How to Clean Out a Central Air Conditioner

What You'll Need
Stiff-bristle brush
Chlorine bleach
Grass and weed trimmer
Soft-bristle brush
Fin comb
Coil cleaner
Carpenter level
Hand mirror

Knowing when to clean your central air conditioner is not always easy. Without actually looking inside the unit, you may never know about excess dirt and dust that have collected there. Consequently, your air conditioner may be operating at less than it's normal efficiency and may be using more electrical power than is necessary. You can easily correct this by cleaning your air conditioner and get it running efficiently again, just by following these 6 simple steps.

Step 1 -  Preparation

Cleaning your air conditioner properly will require you to clean both the evaporator, which you can find inside your home near your furnace, and the condenser which you will find outside your house. To prepare for cleaning, turn off electrical power to both these units at your circuit breaker panel.

Step 2 – Gaining Access to the Evaporator Unit's Interior

Remove the insulation you'll find on the front of the plenum (air duct or space). This insulation may be secured by tape. If so, use care in removing it. You will need to use it to re-tape the insulation when you are finished cleaning. Next, remove the access plate to expose the evaporator. Typically, you will need to remove screws that are holding this plate in place.

Step 3 – Cleaning the Evaporator Unit

Using a stiff-bristle brush, scrub the surfaces of the evaporator unit, including the surface beneath it. If you are unable to get into position to see beneath the unit, use a hand held mirror. Clean off all surfaces, being careful to avoid bending pipes beneath the unit.

Step 4 – Cleaning the Evaporator Tray

Locate the weep hole of the evaporator unit tray and add a teaspoon of chlorine bleach to it to kill any fungus residing there, and to prevent more from growing. If the weep hole is clogged, you can open it by inserting a wire or the end of a wire clothes hanger through the clogged hole. When finished, return the plate and insulation to their original position.

Step 5 – Cleaning the Condenser Unit

At the condenser unit, examine its interior for grass, weeds, or other debris that might have collected or grown inside the unit and might be interfering with the flow of air into the unit. When you have cleared away this debris, use a fin comb to straighten any fins that might have become bent. Then, use a coil cleaner to clean the condenser coil. If you haven't used a coil cleaner and are unsure as to how to use it, refer to the instructions you'll find on the cleaner's container.

Step 6 – Leveling the Condenser Unit

The pad on which the condenser unit is resting must provide a level surface for the unit. Use a carpenter's level to determine if the condenser is level. If it is not, use a pry bar and raise the condenser enough to place shims or gravel under it to make and keep it in a level position.

When finished, return to your breaker panel and restore power to the condenser and evaporator.