How to Maintain an Air Conditioner

A properly maintained air conditioner will cool your home for years. It's easy to do, only takes a little time and by maintaining your air conditioner you won't have to worry the next time a heat wave rolls in. Here's how to make sure your air conditioner doesn't let you down.

Maintain the unit's filters

  1. Unplug the air conditioner and remove the front cover. The filter itself may be attached to the back or the front cover or fastened in front of the coils.
  2. Remove the filter and then wash it in soap and warm water. Squeeze out as much water as possible and let the filter dry before reinstalling it. Replace a damaged or torn filter.
  3. Wipe the cover itself as well as the grill over the evaporator coils.
  4. Vacuum the grill and evaporator coils gently. The aluminum fins on the coils are easily bent, so treat them with care.

Clean and flush the drainage system

  1. Remove the drain tube from the air conditioner.
  2. Clear any blockages in the drain tube by running a piece of wire or a bottlebrush through the tube.
  3. Clean the tube itself by pouring a cup of chlorine bleach and water through the tube.

Things You Will Need

  • Shop vac plus soap and water
  • Chlorine bleach
  • Screwdriver to remove cover
  • Piece of wire or bottlebrush for cleaning drainage tube


  • Turn the air conditioner down (or better yet - off) if you are going to be out of the room for a day or more (even if you are just going to work). This will give the fan in the unit a break and as an added bonus, save on your electrical bill.
  • Install a window air conditioner out of direct sunlight if at all possible. North- or South-facing walls are better than East- or West-facing, since they don't get direct sun.
  • Ensure that the seams all around the air conditioner are well sealed. This keeps the hot air outside and the cool air inside.
  • Remove a window unit during the winter. If this isn't possible, cover it to protect if from debris and winter weather.
  • Keeping an air conditioner's coils, fins and filters clean will ensure that it operates efficiently. A poorly maintained air conditioner not only loses efficiency (and cooling capability), but costs more to run.

About the Author

I learned home repair and maintenance hands on. Over the past 30 years I've built sheds, decks, fences and gates and planted numerous trees and shrubs. Inside I've done all the common jobs like repairing and installing toilets, plumbing and light fixtures plus I've transformed three basements from bare concrete floors and walls into warm , bright family rooms. I write on home maintenance and repair for DoItYourself.com and answer maintenance and repair questions online at MyHomeImprovement.com.