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Why Does My Air Conditioner Turn Off By Itself?

By July 17, 2023Air
Inspect your HVAC unit to ensure everything is working properly.

Having an HVAC unit that works during the hottest parts of the year is vital. When your air conditioner starts to malfunction, things can get very uncomfortable in the home. Not only can you lose energy efficiency, but you are also messing with the lifespan of the air conditioner. Why does my air conditioner turn off by itself? Short cycling and electrical issues are just a few reasons why your ac will cycle off.

Let’s take a look below at some more details regarding your air conditioner turning off by itself.

What Are The Main Causes?

Believe it or not, there are a variety of reasons why an air conditioner might turn itself off. Let’s take a look below at why short cycling is occurring in your air conditioner.

  • Refrigerant issues – If the refrigerant is leaking this will disrupt the cooling process. Proper refrigerant levels are necessary to prevent short-cycling air conditioners. Frozen evaporator coils are also caused by low refrigerant. Short cycling can occur as a result of low refrigerant in your air conditioning unit.
  • Evaporator coil issues – The purpose of the evaporator coil is to remove heat from the inside and blow it back into the home. When the coils get dirty the air is blocked and condensation will build up on the coils. This will cause the coils to freeze. Frozen evaporator coils will cause the air conditioner to short cycle and shut off.
  • Wrong-sized air conditioner – Often builders will install the cheapest air conditioner to pass inspection of the new home build. Installing the wrong-sized air conditioner, whether it is too big for the home or too small for the home will cause it to reach the set temperature and shut down. Having a unit too big will actually stress the system and cause an ineffective cooling process.
  • Dirty air filter – Clogged or dirty old air filters will limit how much air makes it through your ac system. If the air cannot enter and leave your air conditioner, the evaporator coils will freeze. As stated above, this will cause short cycling and the system to shut off. Replace or clean your air filter so that you can avoid this from happening.
  • Compressor – The compressor is meant to keep your system pressurized so that the refrigerant can absorb and remove the heat energy in the home. If the compressor is damaged, it will not work properly. Consequently, the system will shut off more frequently.
  • Faulty run capacitor – The run capacitor provides the air conditioner unit with the necessary electricity to function. Electricity to the cooling unit and the air conditioner itself is what the capacitor provides. Failure of the run capacitor will cause the system to turn on and off more quickly.
  • Other Electrical problems – The moment that the air conditioner has an electrical problem, it will go into a short-cycling mode. Consequently, the typical electrical problems consist of a bad connection, a damaged thermostat, a malfunctioning compressor or condenser, and a bad circuit breaker. Calling a licensed electrician is necessary at this point.

Other Recommended Maintenance

Now that you know why your air conditioner turns off by itself, let’s take a look at some other areas of maintenance.

One of those is home insurance and the HVAC. Unfortunately, home insurance does not cover the HVAC, unless it is an uncontrollable circumstance that caused the damage.

Another area is the life of an HVAC. The number of years you will get out of your HVAC will depend on if it is the right size for your home if it was installed correctly, if you live in a coastal area, or if there are chemicals used in the home. However, the average life of an HVAC is 10-17 years in many places.

Lastly, if it is winter and your furnace won’t turn on, you need to know why. It can be due to the circuit breaker, thermostat setting, needing a clean furnace filter, pilot light being out, or blower motor not working to name a few.

Checking the thermostat to make sure it is set correctly is a good start.

When Do I Call A Professional?

If you are constantly concerned about your AC unit cycling off on its own, then you will need to call a licensed HVAC technician to come out and assess the unit. Additionally, you can call on your local home inspection team to come out and take a look at the electrical system that feeds the HVAC unit power. Also, your local home inspection team can refer a reputable licensed HVAC technician to conduct the service of the unit.


Not knowing how to properly test and inspect your air conditioner is the only reason you need to call a professional. The moment that you start to notice your air conditioner is short cycling or acting up, you will want to call a licensed HVAC service technician. Additionally, this would be a great time to call on your local home inspection team to get a full home inspection. Knowing if the other systems in your home are functioning properly is key. Reach out to Alpha building inspections for a full home inspection in Merrimack, New Hampshire, and surrounding areas.