HVAC Repair Tips


Usually, an AC cycle lasts for about 15 minutes. However, when an AC keeps turning on and off constantly in short intervals of time, it’s known as short cycling.  This is something you should not ignore because it can damage the components of your central air conditioning unit. Some of the fixes for this problem are simple and you can carry out yourself while some others require you to contact HVAC repair services.

Change The Location Of Your Thermostat

Your AC’s thermostat controls the temperature and tells the system when to start and turn off cooling. If the thermostat is located in the wrong part of your house, it may show incorrect readings and the AC may turn on and off repeatedly. This problem can also lead to an AC running constantly for more than 20 minutes.

Therefore, check if the location of the thermostat is correct. Some wrong locations for a thermostat are near the supply air vents, near the hottest or coldest room of the house, or close to a window where the thermostat is exposed to direct sunlight. If your thermostat is located in a similar place, move it to another location. An AC expert can check out the house and suggest the right location for the thermostat.

Thermostat Problems

After ensuring that the location of your thermostat is correct, you should get into inspecting the thermostat itself because a faulty thermostat is a common reason for a short cycling AC.

Your thermostat can be showing incorrect readings due to dead batteries. A common sign of the low battery power of a thermostat is a blank screen. So, replace the batteries, restart the thermostat, and check again.

After replacing the batteries, if your thermostat doesn’t respond to changed settings, it may be malfunctioning. Moreover, you should set the thermostat and after a day check the settings again. If the thermostat forgets the settings, it may be broken.

To make sure your thermostat is bad, get an expert to check the thermostat and your HVAC system.

Clean Or Replace The Air Filter

Air filters should be the first thing you should check if you experience any issues with your air conditioner. We mentioned thermostat-related issues first because they are more common reasons for an AC short cycling than any other reason.

Air filters keep things clean and, in the process, become clogged with the particles they block. When the air filters become dirty, the AC becomes strained due to poor airflow. Among other issues, the AC may begin to turn on and off repeatedly.

So, check your air filters. If they are disposable (plastic-framed), replace them. However, if they are washable (metal-framed), clean them, and reuse them. Usually, you should clean or replace air filters every 2 weeks if you use the HVAC system daily.

Determine The Size Of Your AC Unit

If you have an oversized AC installed, it will short cycle because it reaches the programmed temperature quickly and the thermostat signals it to turn off. A clear sign that your AC is oversized for your home is that the AC has been short cycling since its installation.

For some people, an oversized AC may not be troubling because the AC will still be cooling the home. However, the short cycling of an air conditioner leads to high energy bills, frequent repairs, and a shorter lifespan of the unit.

So, get an expert to determine the size of your AC with respect to the size of your house. If it’s too large for your home, replace it with the suggested size.

Clean The Condenser Coils

Usually, condenser coils become dirty more quickly because the condenser unit is placed outside. When they do, the AC shows that with problems like the AC losing its cooling capacity, blowing warm air, running longer, short cycling, ice buildup on the coils, and others.

Cleaning the condenser coil is easy. You should:

  • Turn off the power to the AC unit from the breaker.
  • Reach the condenser unit and remove the top and side covers of the unit.
  • Clean any dust and debris on and inside the condenser unit.
  • Then, use a vacuum for cleaning the unit.
  • Get a coil cleaner made for cleaning AC coils and spray it on the coils.
  • Then, spray water on the coils for cleaning the coils. You can also use a water hose.
  • Put the covers of the condenser unit back in their place.

Check Out The Refrigerant Levels

Refrigerant is the coolant in AC coils that helps in cooling or heating a house. A refrigerant leak leads to low refrigerant levels. Low refrigerant can cause many issues like short cycling, taking longer to cool the house, frost on the coils, water leakage, and higher electric bills.

Determining the refrigerant levels of an AC is complex and it should be done by an expert only. The expert will inspect the unit, check for leaks, fix the leaks, and then fill up the refrigerant. If you want to inspect the unit for leaks yourself, go near the components of the AC like the air handler and the condenser unit, and listen to the sounds. If you hear a hissing or bubbling sound, it hints at refrigerant leakage. Hire an AC technician to find the exact spot of the leaks and fix them.

If a technician tells you to fill up the refrigerant without fixing the leaks, avoid working with them. This is because the refrigerant levels become low due to a leak. So, if the leak is not fixed, even when the refrigerant is filled up, the levels will go low after some time again.

AC Wiring

Any problems with the wiring can cause an AC to turn on and off constantly. Loose, corroded, or damaged wires can malfunction and cut power to the AC leading to short cycling. If your AC short cycles quite randomly or turns off quickly after turning on (within a minute), then it can be a cause of the problem as well.

Electrical connections and wiring of an AC must only be inspected and fixed by an air conditioner technician.

Compressor Failure

The compressor pumps refrigerant through AC coils for cooling or heating. When an AC cycles on, the compressor starts, and when it cycles off, the compressor shuts down. However, if your AC shuts off only a few minutes after turning on, and keeps repeating this, then it can be an issue with the compressor.

A malfunctioning or overheating compressor won’t perform well and turns off without any signal from the thermostat. If you hear a ticking, chattering, or rattling noise from the AC unit, it can due to a faulty compressor. Plus, an overheating compressor trips the circuit breaker repeatedly.

Check The Run Capacitor

The run capacitor of an AC provides the jolt of power for the motor to run at first. A malfunctioning capacitor won’t store charge properly and the AC might short cycle. A run capacitor is located inside the condenser unit. Let an expert replace it because even if the AC is turned off, the capacitor may hold a charge.


An AC that keeps turning on and off may not cool indoors properly, blow warm air, or cause damage to the components. So, follow the above-mentioned tips to fix this issue. Better yet, hire air conditioner repair services McLean for fixing your short-cycling HVAC unit.


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