Difficulty: 1 of 5


A well-maintained air conditioner will run more efficiently, saving you money on utility bills.


Make sure that electrical power is disconnected from the air conditioner unit before servicing. Window units should be unplugged; central air units should be turned off at the fuse box. For specifics about servicing your specific air conditioner, always refer to the service manual for instructions and safety warnings.


– Bucket
– Garden hose
– Insulation foam
– Knife
– Rake
– Replacement filter
– Screwdriver
– Soap
– Soft brush

Step 1: Central Air Conditioning Unit. Shut off power to the unit.

For a central air conditioning unit, begin by shutting off power to the unit at the electrical panel. Find the switch for the air conditioning circuit and turn it off.
Turn off power at the panel.

Step 2: Clean the area around the unit.

Central air conditioning systems have units outside the house that work with components inside the house to cool the air. Start by cleaning away any leaves, dirt or debris surrounding the unit.

Use a rake to clean the area around the unit.

Step 3: Straighten the fins on the evaporator.

Straighten the fins on the evaporator. Bent fins block the free flow of air. You can use the blade of a small rounded knife or you can use a special fin comb available from air conditioner supply houses.

Use a knife to straighten the fins.

Step 4: Wash and rinse the fins.

Wash the fins with a soft brush and soapy water to remove any dirt buildup between the fins. The goal is to have air pass unrestricted through the unit. Once the fins are washed, rinse them clean with a garden hose. Don’t use too much water pressure or you may damage the cooling fins.

Wash the fins with a brush and soapy water.

Step 5: Remove the old air filter.

Inside the house, replace the air filter by removing the cover in the ventilation duct and pulling out the old filter.

Remove the old filter and inspect for dirt and signs of wear.

Step 6: Add a replacement filter if necessary.

If the old filter is dirty, replace it with a new filter. Slide the replacement filter into the unit and replace the cover.
Compare the new filter to an old one.

Step 7: Restore power to the system.

With the air conditioner unit cleaned and a new filter in place, the system is ready to be used again. Turn power back on at the electrical panel and enjoy the efficient operation of the tuned-up air conditioning system.
Turn the switch back on at the panel.

Step 8: Window Air Conditioning Unit. Remove the unit from the window.

A window unit requires similar care for tuning up. First, unplug the unit and remove it from the window. Place it outdoors in an area that you will use for cleaning.
Put the unit outside for cleaning.

Step 9: Wash the fins with soapy water.

Wash the fins and the outside of the unit with soapy water. Rinse the unit lightly with water.

Wash the fins with a brush and soapy water.

Step 10: Remove the filter.

Remove the inside filter unit from the air conditioner.
Remove the dirty filter.

Step 11: Wash the filter.

Wash the filter in soapy water then rinse in clear water and set aside to dry.
Wash the filter.

Step 12: Inspect and replace the seal around the unit.

While replacing the unit in the window, inspect the seal around the frame of the unit. If the seal has become damaged by water or the Sun’s rays, or if it is missing, you can replace the original seal or add a seal with insulation foam. Cut the foam to fit the edges and then peel off the paper backing and apply the new foam.

Apply the new foam strip to make a seal.

Step 13: Plug the unit in.

With the unit tightly in place in the window, plug it in, set it to an energy-saving temperature and enjoy another season of energy-efficient cooling.
Set the unit for energy savings.