Keeping Your Air Conditioning Working All Summer Long

« Back to Home

Troubleshooting & Fixing an Air Conditioner That Blows Hot Air

Posted on

Nothing is quite as discouraging on a hot summer day as flipping on the air conditioner and being greeted with a burst of hot air. Sometimes it happens because your air conditioner begins blowing air before it has time to cool it. This typically corrects itself in a minute or two. But, when your air conditioner spews hot air into the room with no signs of cooling, you have a more serious problem that requires your attention.

Check out some common reasons air conditioners pump out hot air (instead of a frosty breeze) and learn what you can do to correct it.

Thermostat Settings

There are three ways your thermostat setting can mess with your air conditioner's ability to cool the room.

  1. Warm/Cool Setting: If your unit is part of a central air system, you may have forgotten to flip the switch from warm to cool at the end of the heating season. Solving this problem is as easy as turning the switch to cool and letting your air conditioner work its magic.
  2. On vs Auto: If your air conditioner is set on the "on" position, the fan will continue to blow, even when the air conditioner is not cooling the air. Setting it to "auto" means the fan will kick on when there is plenty of cool air to blow into the room. If your air conditioner is blowing warm air, check that the switch is set to "auto" and it should correct the problem.
  3. Temperature Setting: The temperature setting on your air conditioner regulates often frequently the conditioner will cool the air. If the temperature dial is set too high, you air conditioner will not cool the air properly. Check the temperature setting and adjust it to the desired comfort level.

Clogged Filters

Filters remove dust, pet hair and other debris from the air before the air is circulated through the unit. Under normal circumstances that means you enjoy fresh, cooled air. Sometimes, the air filter can get clogged and restrict the airflow to your air conditioning unit. When this happens, your air condition must work harder (and give off more heat) to cool the air. A clogged filter can cause your air conditioner to pump warm air into the room.

You should clean or replace the air filter in your air conditioner regularly. Your A/C technician typically replaces the air filter during your yearly inspection and cleaning, but if you have pets or live in a dusty area the filter may clog sooner.

Dirty Compressor Coils

The outside of your air conditioner contains the condenser coils. Part of  their job is to release the heat your air conditioner removed from the air. When the coils are covered with dirt and debris, they cannot release the excess heat to the outside. Fallen leaves, pine needles and dirt and debris can collect on the condenser coils making it more difficult for the unit to work properly. Weeds, brush and shrubs growing too close to the air conditioning unit can also restrict the release of hot air.

You can remove fallen leaves and debris from the coils. Cut back weeds, shrubs and other plant material to allow 2 feet between the air conditioner and the plants. Remove any other debris. You can wash the coils with coil cleaner and your garden hose. Unplug or turn off the electricity to the unit and remove any loose debris. Spray the unit with coil cleaner, following the manufacturer's instructions, and allow it to set for the recommended time. Rinse away the cleaner and soil with a garden hose.

If these troubleshooting tips and solutions don't take care of the problem, you could have a leak in the refrigerant line or another malfunction with the unit. Call your local air conditioning service technician to determine the cause.