How to Replace a Central Air Conditioner Filter

Central air conditioning units require continued maintenance to ensure that they run efficiently and properly. Central air conditioning filters should be replaced at the beginning of each new season, typically winter and summer. Neglecting to replace the filter can cause damage to your unit and decrease the air quality inside your home. You can purchase a replacement air filter for your system at any local hardware shop or Wal-Mart. Replacing your filter involves only a few steps.

Step 1

Disconnect power on your central air conditioning unit by turning off the circuit breaker that controls the furnace and unit.

Step 2

Locate the central air unit outside your house and remove all debris from around your unit. Straighten any bent cooling fins, located around the outside perimeter of the unit, and wash with a garden hose on low pressure.

Step 3

Locate the furnace and remove the old, dirty filter. Remove the screws holding the filter cover in place and keep them in a safe place. The filter cover is located where the furnace meets the air duct and is labeled "filter". Remove the filter cover in the venting duct and pull out the filter.

Step 4

Slide in a replacement filter and replace the filter cover. Follow the arrows printed on the filter replacement to ensure you place it in the correct direction. Replace and tighten the screws to ensure the cover is secure in place.

Step 5

Turn on the circuit breaker to restore power. Your central air conditioning unit is now ready for another season.


  • To avoid electrical shock, do not begin any work to the air conditioning unit or the furnace until power is shut off by turning off the circuit breaker.

About the Author

Johnathan Cronk is a freelance writer and began writing at the age of 18. Throughout his career he has specialized in sports, how-to and advice articles. He has also written sales pitches in the corporate setting since 2001. He studied business at Hudson Valley Community College before transferring to the State University of New York, Albany.