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Why Does an Air Conditioner Short-Cycle?

compressor-in-ac-unitOne of the most common signs of something wrong with a central air conditioning system is short-cycling. This is when an air conditioner fails to complete a full cooling cycle and instead shuts down early, only to turn back on again a short time later. Short-cycling is bad news for a few reasons:

  • It wastes power, resulting in higher utility bills
  • It puts extra strain on the AC, leading to an early replacement
  • It doesn’t give the system enough time to spread cool air evenly around the house

Under normal circumstances, you can expect your home’s air conditioning system to run for 15 minutes or more before it cycles down. If you notice that it’s running for shorter times than this and you hear it turn on multiple times in an hour, you should look into it. Sometimes short-cycling is a simple issue to correct. But in many cases, you’ll need to call technicians to diagnose what’s happening and then handle the necessary air conditioning repair in Fresno, CA.

One of the difficulties of short-cycling is that there are many different sources for it. This is why a proper professional diagnosis is important. Below are some of the causes of a short-cycling AC.

  • The air filter is clogged: We can never emphasize this enough—clogged filters are responsible for numerous AC problems, so make sure you have a new filter put in place every one to three months. A clogged filter can put enough pressure on the blower fan to cause the AC to shut down early.
  • The thermostat is malfunctioning: The thermostat may be reading incorrect temperatures inside the house, and this will cause it to signal to the AC compressor that its job is done. Please don’t try adjusting the thermostat to correct for this! Let technicians find out if the thermostat is the problem and recalibrate it if it is.
  • The refrigerant is leaking: Short-cycling is one of the warning signs of an air conditioner that is losing refrigerant to leaks. This is an easy problem for our repair experts to correct, but it’s also one that can have catastrophic results if it isn’t fixed soon. Letting an AC run with a low refrigerant charge can cause the compressor to burn out.
  • The evaporator coil is frozen: There should never be ice on the AC, anywhere. If it starts to form on the evaporator coil, the AC will begin to lose its cooling power and short-cycle. If you see a frozen evaporator coil, don’t try to defrost the ice or scrape it off yourself. You need technicians to repair the underlying problem.
  • The air conditioner is oversized: If this is a new air conditioner that has started to short-cycle, the issue may be that it was incorrectly sized so it’s too powerful for the house. The AC sends out so much cooled air that the thermostat falsely registers the house is at the target temperature and turns off the compressor early. The only way to correct this is to have experienced professionals replace the AC with one that’s the right size.

Rely on Purl’s Sheet Metal & Air Conditioning for your AC repairs each summer. “Quality Is the Cornerstone of Our Success” since 1952.

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