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Why is My Air Conditioner Turning On and Off? Hear from a Phoenix Tech

2019 Jul 15
Posted in:
What Temperature Should You Set Your AC When You're Away? A Phoenix Tech Answers

If your AC is turning on and off, it can cause some serious issues, like:

  • Increased wear and tear on your system
  • Spike in energy bills
  • Expensive repairs or replacements
  • Decreased comfort

A few of the most common reasons your AC will turn on and off are: 

  • AC is too large for your home
  • Refrigerant levels are low
  • Thermostat location 
  • Dirty air filter

Below, we’ll walk through each of these issues to give you a better idea of what could be causing your AC to turn on and off and what you can do to fix it.

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Reason #1: Your AC is too large for your home

If your AC is too large for your home, it will cool your home quickly and shut off. If you recently had your AC system installed and have been noticing this issue since then, this is likely your issue. 

The solution: Contact a professional to conduct a load calculation and help you determine what size AC is right for your home. 


Reason #2: Low refrigerant

Your AC cools your home by taking the warmth out of the air and dumping it outside. Refrigerant is the substance that absorbs the heat from your home’s air and carries it outside. If your refrigerant lines are low on refrigerant, it can lower the pressure of your entire system, affecting the indoor unit’s ability to do its job.

Most AC systems have a safety feature that shuts the system off when it senses that refrigerant levels are low. This can result in the constant on/off cycle you’re noticing.

The solution: Contact an HVAC technician. If your refrigerant is low, there is likely a leak in the refrigerant lines. A professional will need to check your refrigerant lines and fix the leak before refilling the refrigerant.  


Reason #3: Dirty air filter 

As we mentioned above, your AC cools your home by taking in warm air from your home and stripping that air of heat. 

A dirty air filter can restrict airflow to your indoor AC unit, causing your evaporator coil to freeze. 

Your AC has built-in safety devices that will shut off your AC when it notices that certain parts are malfunctioning, like a frozen evaporator coil. So, if your evaporator coil is frozen, this could explain why your system is continuously shutting on and off.

The solution: Check your air filter and replace it if it’s dirty. If your air filter looks like the filter on the right, turn your AC off for a few hours to allow the ice on your evaporator coil to melt.



Once you turn your AC back on, it should be working normally.

If your AC continues to turn on and off even after you’ve replaced the filter, you should contact a professional. If your evaporator coil has been frozen for a while, this might have resulted in damage to the outdoor unit. A professional can check out your AC system and make any necessary repairs. 


Reason #4: Thermostat location 

Your thermostat’s job is to correctly read the temperature of your home and signal your AC when it needs to cool your home.

If your thermostat is located in a bad area, like close to an AC vent or near a window, it may misread the temperature of your home, causing your system to turn off. Once your thermostat reads that your home is too warm, it will signal your AC system to turn on again. 

The solution: Contact a professional to move your thermostat to a central location in your home. This will help your thermostat correctly read the temperature of your home and prevent your system from turning on and off. 


Want your AC to run efficiently? Hire a George Brazil Pro

Whether you think you’ve pinpointed the AC issue you’re experiencing or you think your problem is not on this list, our team of expert pros can help you figure out the right solution for your system.

Request an appointment today!