Short Cycling AC – What To Do?

Your air conditioner is short cycling, and now you're worried that something is wrong with the unit. We hate to break it to you, but there's definitely a problem with your air conditioner! Constant short cycling is not a good sign. We've researched this problem for you and have information to share on what to do when an air conditioner is short cycling. 

There are several reasons why an air conditioner experiences short cycling. You can try to do the following to fix the problem:

  1. Clean the air filters.
  2. Check for refrigerant leaks.
  3. Avoid frozen evaporator coils.
  4. Relocate the AC thermostat.
  5. Replace oversized AC unit.

Ignoring constant short cycles will take a toll on the lifespan of your air conditioner and eventually your pocket. Read on to learn more about why short cycling happens and why you should never ignore it.

Newly installed ac on a white pastel colored wall, Short Cycling AC - What To Do?

Short Cycling AC - What To Do?

You should try to identify the cause when your AC continuously turns on and off. There are many possible reasons why this happens and some could be as simple as dirty air filters. Sometimes, however, a serious problem exists and you have to call the pros for assistance. 

In the meantime, you can try to resolve the problem. But before we proceed to the quick fixes, it only makes sense that you understand what short cycling is and why it is bad for your AC.

Male hand turns on air-conditioning system

What is Short Cycling and Why It is Bad?

Your air conditioner completes three cycles of cooling per hour on average. Each cooling cycle lasts about 10 minutes, and then the unit shuts down for another 10 minutes after reaching the required temperature. When your air conditioner turns on and off more often than the average, it is short cycling. 

Your air conditioner compressor works harder and uses more energy when it kicks in to start a cooling cycle. The more it has to do that, the more pressure you are putting on your compressor. When the compressor goes through a lot of stress, its components wear down more quickly. You are even putting it at risk of overheating.

When things get even worse, you will end up needing a replacement, which is not cheap, especially without a warranty. When not under warranty, compressor replacement can cost as much as $2500 including the labor fees.

Short cycling does not only affect your air conditioner's lifespan. The longer you ignore the problem, the higher your energy consumption becomes, which also causes your electricity bill to spike.

How to Fix Short Cycling AC

Don't call the pros yet. Try the following quick fixes first when your air conditioner short cycles.

Clean the Air Filters

Dirty air filters can affect the performance of your air conditioner in many ways. Poor airflow restricts the efficiency of different components in your equipment. Most of all, the compressor will have to work hard to perform its role. Once it is overworked, the compressor overheats and shuts down even before it has cooled the room to the required temperature.

Clean Air filter for home central air conditioning system

The compressor will automatically attempt to complete the cooling process as soon as the temperature is back to normal. To avoid this, clean the air filters to improve the airflow inside your equipment.

You simply have to remove the air filters according to the instructions in the manual and then clean them with low vacuuming or mild detergent and water. You should also replace them every 3 months or sooner during the cooling season, as recommended by the US Department of Energy.

View this filter spray on Amazon.

Check for Refrigerant Leaks

Coolant is also an important component in any air conditioning unit. It runs through the coils to produce cool air.

When the coolant level is below the normal range, it will struggle to cool warm air no matter how hard the compressor works. Again, the compressor overheats causing a series of short cycles.

Did you know that the coolant in an air conditioning unit does not need replacement at all? The supply is enough to last a lifetime. Air conditioning coolant is sealed in a loop which only means leakage when the coolant level drops below normal.  

Asian male air technician is checking the compressor and filling it up for home and building air conditioners

It is likely that your AC has a refrigerant leak when it takes longer to cool the room and your electricity consumption is noticeably higher than usual. A frozen coil may also indicate that a leak is present. 

The best way to handle a refrigerant leak is to get professional servicing. Only HVAC contractors can refill AC refrigerants, unless you have the tools and general knowledge about air conditioners.

Avoid Frozen Evaporator Coils

In addition to a refrigerant leak, the evaporator coils could freeze due to poor airflow. Weak airflow hampers your AC's ability to retain heat and function properly. 

To improve the airflow and avoid frozen coils, you should clean the filters and vents regularly. Inspect the blowers, too, to make sure that they are working properly.

Ensure Correct Thermostat Placement

Where you place the thermostat in your house can also affect the cooling cycle of your air conditioner. Make sure it is not located near any heat source.

One hand adjust thermostat digital in fahrenheit at home

Placing the thermostat near a window where it receives direct sunlight or near an appliance that emits heat might send wrong signals to the device. Then it will instruct your air conditioner to start back up and cool more air.

Check the thermostat placement and relocate it when necessary.

Replace Oversized AC Unit

It is wrong to think that you are one step ahead with an oversized AC. While it can cool the room faster because of the large capacity, it no longer operates according to its normal cooling cycle. It shuts down and starts back up again more frequently than it would within a room of the proper size.

An oversized AC is more prone to wear and tear. You would have to replace your equipment sooner than when you use the right size for your home. Furthermore, your energy consumption increases along with your monthly electric bills. 

If possible, replace your unit and invest in proper AC installation.

Can Too Much Refrigerant Cause Short Cycling?

When an AC is over-charged with freon or coolant, it will not work efficiently. All air conditioners maintain specific pressures and coolant levels, but when these requirements are not met, your equipment stops working the moment they are detected. 

Too much coolant hinders the operation of any of the metering devices such as the thermostatic expansion valve. The fluctuations in readings cause constant on and off cycles.

How to Avoid a Short Cycling AC

Keeping your air conditioner in tip-top shape starts with proper sizing and installation. Let the HVAC contractor handle this job to minimize premature failure of any of its parts.

If the AC is already installed, the best way to avoid any air conditioner problems including short cycling is proper and regular maintenance.

Nothing beats professional checks and cleaning, but your equipment should be fine when it is checked at least once a year. This doesn't mean that you should wait this long to clean the system. 

Clean it every 3 months or as soon as needed. Proper airflow is crucial for any AC unit to work efficiently. Poor airflow can affect different AC components all at one time and lead to repairs. You should get rid of dust in your inside and outside units as frequently as possible.

You can read these related posts on AC cleaning and maintenance for more useful information:

How To Clean A Carrier Air Conditioner Filter

How To Clean A Ductless Air Conditioner [Including The Filter]

When to Call Professional Servicing for AC Short Cycling

If the problem does not resolve with cleaning and quick fixes, then it's time to call your HVAC contractor. Short cycling needs immediate attention or it will progress and result in serious repairs. It is very likely that the compressor will break down after all the stress it goes through during cycle startups. 

Compressors are almost impossible to fix when they break down. Without it, there's no way your AC can produce cool air. Make sure to watch out for signs such as screeching, buzzing, and other strange noises, as well as low air output, which already indicate a compressor problem.

Final Thoughts

Newly installed ac on a white pastel colored wall

In this post, we covered the reasons why an AC short cycles, why you shouldn't ignore it, and what you can do to fix the problem. You should consider short cycling a serious air conditioner issue—one that needs immediate attention. For major repairs, calling your HVAC contractor remains the best option. 



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