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Why Is My Air Conditioning Unit Blowing Hot Air?

Air conditioning unit outside a houseWhen summer temperatures reach their peak heat, you want to make sure that your air conditioning unit is performing at its best. If there is warm or hot air coming from your unit, it might be time to call in a professional. However, there are a few things you can check first.

Most air conditioning units have two main components – one part is indoors, and the other is outdoors. Both work together to remove heat from your home.

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The Most Common Causes That You Can Fix or Diagnose on Your Own Include:

  • Check the thermostat. It may be set incorrectly – make sure it is not set to heat. If the thermostat is set to “on” instead of “auto,” the fan will blow even when the air conditioner isn’t cooling and can cause warmer air to blow out the vents when the outside unit isn’t running.
  • Check the compressor (the outside unit) to make sure it is functioning properly.
  • Dirty coils or general maintenance may need to be performed.
  • The outside unit could be clogged with leaves or debris, so make sure everything is cleared away from the unit. Trim bushes, weeds, tall grass and etc. near the unit that could restrict airflow.
  • Make sure your outside unit is receiving electricity. A circuit breaker may have been tripped, or a fuse could have blown.
  • Replace the filter on your indoor air handler.
  • A restriction in the airflow can result in less air coming out of the vents, which will make your home feel hotter. Restricted airflow also can cause the unit’s compressor to freeze up.
  • A return duct could be broken or disconnected and pulling unconditioned air from the outside.

If your air conditioning unit continues to trip a circuit breaker, call a professional right away, as this is a sign of a more serious problem. Other situations where you should call in a professional include low Freon or refrigerant, leaks, a dirty evaporator coil, and a broken or disconnected return duct.

RELATED: 10 of the most frequently asked HVAC questions

It’s always a good idea to hire a professional to inspect and perform maintenance on your system every spring for the air conditioner and every fall for the heating unit. A professional can inspect and clean the wiring and mechanisms of each of the units and take care of the more challenging maintenance work.

A few other tips to follow include only using your air conditioner when outdoor temperatures are higher, not during moderate weather. Keep blinds or drapes drawn during the hottest parts of the day. Install awnings over windows exposed to direct sunlight, and don’t run exhaust fans longer than necessary. Rising heat from lamps and other heat-producing devices can cause the air conditioning system to over-cool your home, so only use these devices when necessary.

Keeping up with regular maintenance can save you money and energy while prolonging the lifespan of your system. On the first hot day of summer, the last thing you want is an air conditioner that won’t run. Do the proper maintenance before summer arrives so your unit can cool your home efficiently.

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