Why Won’t Your Central Air Conditioner Turn Off?

The temperatures are rising, and your central air conditioner seems to be running nonstop. If your central AC is running properly, it will cycle on and off, according to your thermostat's setting. When your AC runs constantly and doesn't cycle off when the desired temperature is reached, it is a serious problem. Not only does a constantly running AC cost you a lot of money, but the issue can also cause unnecessary wear and tear to your system.

Here are a few of the most common reasons why your central AC runs constantly.

Dirty or Damaged Air Filter

Whenever there is an issue with your central air conditioner, the culprit is often your air filter. Depending on the size of your home's AC, the number of pets, and the type of filter, you should change your air filter every few weeks. A dirty air filter does not allow air to flow sufficiently through the system, which can cause a host of problems, including a unit that does not shut off properly.

Contact an HVAC technician if you aren't sure how often to change the air filter, where to locate the filter, and which variety of filters is the best choice for your system.

Check Your Thermostat

Check out the fan setting on your thermostat. The fan should be set to "Auto," which means that the fan only turns on when the AC is triggered. If the fan is set to "On" it will run continuously. If you did this and the AC is still continuously running, the problem might be a faulty thermostat. An HVAC technician can test the thermostat to determine if it is properly cooling your home.

Faulty Fan Limit Switch

The air conditioner's fan limit switch has an important function: it helps determine when the blower fan turns off and on. If the fan limit switch is faulty, or dirty, or there is an issue with the sensor, the fan will not turn off. Once again, because it is tricky to diagnose a faulty limit switch, it is a job best left to the professionals.

The Central AC Is Too Small for the House

Finally, if you get a new AC installed in your home, and the AC is constantly running and never seems to turn off, the issue might be the size of your central air conditioning system. AC systems come in a variety of sizes and if you purchase a system that cannot support the size of your home, it will run more often to keep the home at temperature.

From a faulty fan limit switch to a dirty air filter, there are several reasons why your AC is constantly running. Contact a local HVAC repair service to learn more.