Filter, Power Cord, Coils, Switch, Drain Ports, Motor and Compressor

The filter, power cord, coils, switch, thermostat, drain ports, and fan are important to service on a routine basis to avoid larger problems. Below are guidelines on how to maintain these key parts.

Filter

At the beginning of every cooling season and once a month during the season, remove the front grille and clean or replace the filter. If you live in a very dusty area, clean or replace the filter more often. Most room air conditioners have a washable filter that looks like sponge rubber.

Clean the filter with a solution of mild household detergent and water; rinse well. Let the filter dry completely before reinstalling it. Some units have a throwaway filter, similar to a furnace filter. When this type of filter becomes dirty, replace it with a new one of the same type.

Power Cord

The power cord that connects the air conditioner to the wall outlet may become worn and fail to supply electricity to the unit. To check the cord, remove the control panel. Unscrew the cord terminals and then attach a test wire across the bare lead wires.

Hook the clips of a volt-ohm-milliammeter (VOM) set to the RX1 scale to the prongs of the cord's plug. If the meter reads zero, the cord is functioning. If the meter reads higher than zero, replace the cord.

Evaporator and Condenser Coils

Clean the evaporator and condenser coils at the beginning of the cooling season and every month during the season. If you live in a very dusty area, clean the coils more often. Use a vacuum cleaner on these components.

If the fins on the coils are bent, straighten them with a fin comb, sold at most appliance parts outlets. A fin comb is designed to slide into the spaces between the fins. Use it carefully as the fins are made of light-gauge aluminum and are easily damaged.

Switch

The selector switch, located directly behind the control panel, turns the unit on. If the air conditioner does not run at any setting, and it is receiving power, chances are the switch is faulty. To correct the problem, remove the control panel and locate the switch. Check the switch terminals for burnt insulation or burn marks on the terminals. If you see any indication of burning, replace the switch with a new one of the same type.

The switch is held to the control panel or frame with screws; unscrew it and connect the new one the same way. If you determine the problem may not be the switch, call a professional service person.

Drain Ports

As the air conditioner operates, condensed moisture and water vapor from the evaporator coil are funneled through drain ports or an opening between the partition in the middle of the evaporator coil and the condenser coil. At this point, the fan blows the moisture against the condenser coil, where the water is dissipated.

Drain ports can become clogged with dirt. The result is water leaking from the appliance, usually through the bottom of the grille. To prevent clogging, clean the ports with a short piece of wire hanger or the blade of a pocketknife. Do this at the beginning of every cooling season and every month during the season. Also check the condenser side of the air conditioner. Some models have a drain port along the bottom edge of the cabinet frame. If your air conditioner has this drain port, clean it out when you clean the other ports.

Motor and Compressor

If problems occur in the motor or compressor of the air conditioner, call a professional service person.

The problem may not be in the mechanics of your unit at all; it may be the thermostat. Find out how to check and replace a thermostat on the next page.

For more articles on home repair, check out the following links.

  • How To Repair Central Air Conditioners: If your system sends cool air to all parts of the house, you've got central air. Keep the system running cool.
  • Major Appliance Repair: If the a/c isn't the only thing in your house on the fritz, you can learn how to fix other machines in this article.
  • Small Appliance Repair: Once you've tackled the a/c, a toaster or blender seems like child's play. Find out how to fix them here.
  • Thermostat Maintenance: To make sure there's actually a problem with your a/c, you may want to check the thermostat, too. Learn how to calibrate a thermostat.