How to check your central air conditioner before calling a repair man

When summer heat arrives, you may find the central air conditioner running but your house less cool than you want. When this occurs, you may be tempted to call a repair person immediately and spend hundreds of dollars on a simple repair you could have done yourself.

The central air conditioner's condenser coil lies behind a protective grate.

Before calling the repair shop, check a few things on your own.

  1. Look at the air conditioner return vent inside your home. Pull the filter out of the return vent and check for dirt. Change the filter if it is clogged with dirt, dust or animal fur. If it does not look dirty but has not been changed in awhile, change it anyway given the likelihood of dirt inside the filter that you cannot see. A dirty air filter can cause an air conditioner to freeze up, creating a rise in temperature in the home.

  2. Clean the condenser coil located on the outside unit with a regular garden hose. Turn the unit off. Hold the hose about four inches from the coil and slowly spray it as if you were painting, with a right-to-left motion. That way you do not miss any areas. You cannot see the dirt in the coil until brown water emerges from the bottom of the condenser coil. Allow the unit to dry for 10 minutes before restoring power.

  3. Allow the central air conditioner time to cool the house after restoring power. If you replace an extremely dirty filter and do not see a change in the temperature, the reason is most likely to the unit freezing up. Shut off the unit for several hours so it can thaw before calling a repair shop. If the repairman comes and has to defrost the unit himself, you may have to pay for the time allotted for defrosting.