Why Does Your Air Conditioner Keep Shutting Off During Heat Waves?

23 August 2023
 Categories: , Blog


Summer can be an incredible time of year filled with family road trips and fun beach days. Unfortunately, the summer heat can also quickly become unpleasant. Heat waves can often feel unending, with long, humid days and a sense that relief may never come. Of course, you rely on your air conditioning system to help keep you cool and comfortable during these periods.

When operating correctly, your air conditioner should run until it can satisfy your thermostat's setpoint. If you notice that your air conditioning system shuts down too soon, especially during long stretches of oppressive heat, you may be dealing with a condition known as "short cycling."

Short Cycling: A Simple Definition

Short cycling might sound like a technical term, but it's a relatively easy condition to explain. Your air conditioner runs in cycles, providing cool air for as long as it takes to bring your home to your thermostat's setpoint. Once the system meets the thermostat's demands, it shuts off again until the temperature rises and the next cycle begins.

The cycle length can vary for many reasons, and you can expect your air conditioner to run longer on very hot days. As a result, recognizing short cycling isn't always easy. However, a good clue is whether your system reaches the correct temperature. For example, if you set your thermostat to 68 degrees and it shuts off at a warmer temperature, you may be experiencing short cycling.

How Heat Waves Can Trigger Short Cycling

Short cycling can have numerous underlying causes, and your system may short cycle even when temperatures aren't particularly hot. Still, this problem becomes more apparent when your system operates under a heavy load. During extreme heat waves, your system must run much longer, and it will be more obvious when it shuts down too soon.

Additionally, short cycling often results from frozen evaporator coils. Evaporator coils can freeze due to refrigerant leaks or restrictions and airflow problems. The longer the system runs, the more time ice will have to build up on the coils. The normally long cycles during extreme periods of heat can provide plenty of time for the coils to freeze and your system to begin short cycling.

What You Should Do When You Suspect Short Cycling

Unfortunately, short cycling is more than a minor nuisance. The direct cause of short cycling is usually a safety switch causing your system to shut down, such as your compressor's overheat protection kicking in. While these features theoretically help protect your system from damage, they aren't always foolproof.

When you think your system might be short cycling, a good first step is replacing your air filter since airflow restrictions may allow the evaporator coils to freeze. If this doesn't resolve the problem, stop using your system and contact an HVAC contractor for a service visit. Addressing short cycling issues as soon as you notice them can help you avoid more serious problems with your system.

Contact air conditioning services near you to learn more.