AC Repair FAQ – Why Does My AC Turn On and Off?

You’re sitting on the couch in a quiet room, then suddenly… you hear the telltale noise of your air conditioning starting up. You feel the fan blowing air out of the vents. Moments later, this stops as quickly as it started. Many of our customers here in Los Angeles wonder why their AC unit system turns on and off all day long. And, is that normal behavior?

What LA Homeowners Need To Know About How ACs Work

Your thermostat is the communication center for your air conditioning system. It monitors the temperature inside your home and tells the AC unit when it’s time to turn on and off to maintain the temperature settings you give it. 

When the temperature inside your home rises over the temperature setpoint, the thermostat signals your air conditioner to make cold air. This helps bring down the indoor temperatures. Once the temperature sensor gets a reading below the setpoint, your AC unit will shut off after a job well done.

Changing the mode and setpoint of your thermostat will be the biggest determining factor for your unit turning on and off (we call this “cycling”). This is totally normal throughout typical operation. But there can be too much of a good thing – read on to know when cycling is abnormal for your AC.

When Does Cycling Become A Problem?

If you find your air conditioner is turning on and off quickly, there could be a bigger issue. As mentioned in the section above, it’s normal for your system to cycle.

If the contractor that installed your air conditioner sized the unit correctly, the only time it would not cycle during operation is during the hottest hours of one of the warmest days of the year. Every other day, your AC will only need to turn on and off at 5-10 minute intervals to maintain appropriate indoor temperatures.

When those cycling intervals are much shorter, this is a sign there is a definite problem with your system. We call this behavior short cycling, and it usually happens when the size of your air conditioner is too large for the space it’s cooling. 

Bigger isn’t always better. Short cycling will almost always shorten the lifetime of the unit and its components. It can also potentially cause humidity problems. An oversized unit can cause as much discomfort as an undersized one, so it’s important you reach out to true professionals to help select the right piece of AC equipment for you. 

Modern air conditioners offer a lot of options, like variable speed and staged equipment. These models can operate longer without turning off. This reduces cycling and helps to continuously dehumidify the air in your home.

Next Steps If Your AC Is Turning On and Off Frequently

AC equipment cycling is very normal. But if it’s bothering you, or you think you need someone to take a look at it, reach out to us. 

The best thing you can do to prevent future issues is to schedule regular AC tune ups. We recommend a preventative maintenance agreement, where we will check for these types of problems on an annual basis. 

If you have any concerns about your AC unit turning on and off, or short cycling, don’t hesitate to call us.