8 Reasons Why Air Conditioner Turns Off By Itself

In the summer heat, you count on your air conditioner to be reliable and provide constant cooling comfort. Unfortunately, its numerous moving parts make your AC unit susceptible to functional issues. You might find that your AC is turning off by itself, and you don’t know why. 

When your air conditioner turns off by itself, turns back on, and continues this back-and-forth action, we call it short cycling. Short cycling can damage your unit, produce uncomfortable temperature levels throughout the house, and increase monthly energy bills. The first step in stopping your AC unit from short cycling is identifying why it’s doing so in the first place.

To help you locate the issue, we’ve compiled a list of the eight most common causes of short-cycling issues. Once you’ve found the culprit, you need a reliable HVAC service company in Boiler Springs to resolve the problem. Call Smooth Sailing Heating and Cooling at (864) 689-2303 to schedule an appointment. 



1. Issue With the Thermostat

The thermostat is in charge of sending signals to the air conditioner. When it thinks the AC has cooled your home to your desired temperature, it shuts your AC off. However, certain issues can cause malfunctions even when you have the correct thermostat settings.

Failing batteries or an electrical issue like lousy wiring can cause your thermostat to malfunction and shut the air conditioning down prematurely. 

Other problems stem from the placement of your thermostat. If you set your thermostat up in a dark area of the house or near an air vent, it might read a low and inaccurate indoor temperature and stop the cooling process.

2. Oversized AC Unit

When your AC unit has a higher cooling capacity than is necessary for its room, it will run a much shorter cycle. An oversized air conditioner drops your indoor temperature too quickly and shuts off, not allowing enough time to pull moisture out of the air. The quick cycle results in high indoor humidity, leaving your house feeling muggy regardless of temperature. 

3. Dirty Air Filters

Air filters pull dust and pollutants out of your air to purify it. Over time, these filters get dirty and even clogged, restricting airflow. Without proper airflow, your AC unit may shut down.

4. Frozen Evaporator Coils

Evaporator coils cool the air in your home and send it back through the vents. Restricted airflow can freeze the evaporator coils, or they may freeze if they’re too dirty. When that happens, your HVAC system works overtime to defrost the coils and may overheat, malfunction, and shut off the AC.

5. Dirty Condenser Coils

Condenser coils also help cool your home, but they do so by sending hot summer air outside. Because they’re outdoors, condenser coils can easily collect dust and debris. Dirty condenser coils may cause your AC unit to overheat and shut down prematurely. 

6. Insufficient or Leaky Refrigerant

Another reason why an air conditioner turns off by itself is low refrigerant. Refrigerant works within the AC unit’s coils to absorb and dissipate heat. With insufficient refrigerant, that heat exchange won’t function correctly, and the air conditioner may turn off. 

Low refrigerant is almost always due to a leaky refrigerant line, as the levels are self-contained. Leaky refrigerant can lead to several other HVAC issues, so you should call for service immediately if you suspect this issue. 

7. Failing Run Capacitor

The run capacitor provides the power that keeps your air conditioner running. When your run capacitor fails, it often sends intermittent power to the AC unit. Without the necessary power to run continuously, your AC will short cycle. 

8. Electrical Problems

Many electrical problems can be the culprits for a short-cycling air conditioner. Some of these, as we mentioned, are within the thermostat or the run capacitor. Other electrical issues include a bad connection and a faulty circuit board. 

Electrical problems can be challenging to diagnose and even harder to repair. If you suspect an electrical issue is at the heart of your short-cycling AC, call an HVAC technician to handle it safely. 

Call Smooth Sailing Heating and Cooling Today

If your air conditioner turns off by itself, the first step is diagnosing the issue. Once you do so, call Smooth Sailing Heating and Cooling.

While homeowners can solve some of these short-cycling problems, such as changing the thermostat’s batteries or replacing the air filters, most are jobs for a professional HVAC contractor. Visit our website to learn the risks of DIY AC maintenance.

Call Smooth Sailing Heating and Cooling at (864) 689-2303 to schedule AC service.