Why Does My Central Air Keeping Running After the Temperature Is Reached?

Thermostat Settings

• Look at your thermostat, and see whether the control switch is set to “Cool” instead of “Auto.” When the control is set to “Cool,” the air conditioner continues to run, regardless of whether the home has reached the set temperature point. To reduce energy costs and run the air conditioner only as necessary to reach and maintain the desired temperature, place the thermostat control to “Auto.”

Vents

• Find the supply and return air vents throughout your home, and leave all of the vents open and unobstructed. While shutting the vents in rooms that are not used often may seem to make sense, doing so can create a pressure imbalance that forces the air conditioner to cool the home unevenly, making the set temperature harder to reach or maintain.

Doors and Windows

• Check the doors and windows throughout the home. Leaving exterior doors or windows open allows hot air to enter the house and cool air to exit, causing the air conditioner to run more often and cool continuously to keep the set temperature. In addition, closing interior doors builds up pressure in the closed rooms, forcing the cool air through leaks in the door or windows and causing a temperature imbalance. Close all exterior doors and windows, but leave interior doors open for better air flow and temperature control.

Air Filter

• A dirty air filter is another reason why the air conditioner may not run efficiently and cools the house to the wrong temperature. First, disconnect power to the air conditioner, and then open the access panel on the main air conditioner unit. Remove the air filter from the filter clips, and pull the filter out. Check to see if the filter is marked “Disposable” and can be replaced or is marked “Permanent” and needs to be cleaned. Clean it by vacuuming or washing the filter thoroughly and then air drying it. Place the filter back into the air conditioner and secure the clips, then shut the access panel firmly and restart the power.