On a hot day, you might need the air conditioning a lot. However, if you start to notice that the cool air shuts off too soon, you might have a problem. Air conditioning units that cycle too frequently and quickly are said to be “short cycling,” which can impact your home comfort, energy efficiency, and the lifespan of the equipment.
If you want to know exactly why your AC keeps turning off and how to stop it, we’ve got you covered. Follow these tips to solve the problem and prevent it from happening again.
Common Causes of Short Cycling
You may be asking yourself, “Why does my air conditioner turn off by itself?” If you always schedule annual HVAC maintenance and keep up on all necessary repairs, you’re probably completely stuck on how to answer this question. However, AC problems can occur at any time.
There are a number of reasons that your air conditioner might be short cycling, but a few are more common than others. These concerns may require repair or replacement:
- Evaporator Coil Issues: The evaporator coil removes heat from the indoor air and allows the blower to circulate it again. If the coil gets dirty, condensation can collect and freeze on the coil. The system works harder to thaw the coil but shuts off quickly due to overheating.
- Refrigerant Problems: Low refrigerant is also a common cause of a frozen evaporator coil. The refrigerant is converted from a vapor to a liquid and back again as part of the process of removing heat. Low refrigerant due to a problem with metering or a hole in the refrigerant line may disrupt the cooling system, prompting short cycling. Signs of a refrigerant leak include strange hissing noises coming from the refrigerant pipe and humid indoor air.
- Poorly-Sized Air Conditioner: Air conditioners are measured by their output. If you have a unit that is too big for the cooling load you place on it, the air conditioner will reach the set temperature too quickly and turn off. While this may seem like a benefit, it actually taxes the equipment and can provide you with ineffective cooling.
- Dirty Air Filter: An old and clogged air filter limits the amount of air entering and leaving your air conditioner. When this happens, your AC’s evaporator coils can freeze, and short cycling can occur. If your house AC keeps shutting off, try cleaning your air filter or replacing it with a new one.
Additional Reasons for Short Cycling
Even after considering all of the possible causes above, you may still be wondering: “Why does my AC keep turning off?” In the end, there are many potential reasons why your central air keeps shutting off, though they might not be as common or well known. These potential causes include:
- Electrical Troubles: An air conditioner needs properly functioning electrical connections to run correctly. Bad electrical connections won’t be able to send signals between the circuit boards, thermometer, and other parts, which could be why your AC keeps shutting off.
- Clogged Drain line: Your AC has drain pans that collect excess moisture caused by humidity. Your AC might keep turning on and off if moisture cannot properly drain due to a clogged drain line.
- Faulty Run Capacitor: Did you know that a run capacitor helps your AC keep running? When a run capacitor malfunctions, your air conditioner will be given power at irregular intervals. This could be why your AC keeps shutting off unexpectedly.
Negative Effects of a Short Cycling Air Conditioner
It is quite possible that an air conditioner could be short cycling for weeks or even months without breaking down in a way that is obvious to you. Here is what you can expect from a system that is short cycling if you do not identify and solve the problem quickly:
- Increased Humidity: You may not know that air conditioners were initially designed to remove humidity from the home as much as heat. An air conditioner that is too big for the home may easily be able to achieve the right temperature but fail to run long enough to remove humidity. This leaves your home feeling muggy and makes the space a more inviting environment for mildew and mold.
- Higher Energy Expenses: Every time the air conditioner turns on, it uses energy. The more it turns on, the more energy is used. As a result, a short cycling air conditioning unit is likely to increase your energy bills. Since short cycling is not considered an efficient use of the machine, you might pay more to feel less comfortable.
- Worn Components: You can typically expect about 10-15 years, or even 20, out of your air conditioner if you get regular maintenance and prompt repairs for it. However, just like your car, it depends on the miles you put on it. Running your air conditioner into the ground with short cycles will wear out the compressor much more quickly, which is one of the most expensive components of the unit.
- Costly repairs: Now that you know why your AC is shutting off, it’s time to discuss the effects the issue can have on your spending. Wear and tear can occur as a result of short cycling. In the end, you could be facing frequent expensive emergency repairs.
Benefits of Professional AC Service
Ultimately, the question of why your AC keeps turning off can be answered with proper and professional HVAC service. Licensed technicians can determine the cause behind your short-cycling AC and offer a proper long-lasting solution, whether that’s a quick repair or a new AC installation.
By having a properly sized AC installed, you don’t have to worry about your air conditioner being too large and shutting off after cooling your home too quickly. After all, ACs that are too large for your home can cause discomfort and even wear out faster than normal. Where there’s wear and tear, costly repairs are never too far behind.
Additionally, professional technicians will be able to perform thorough inspects and accurate repairs on your AC. As a result, your air conditioner will function more efficiently and can live a longer life.
Preventing Short Cycling
The best defense is a good offense—and one that helps keep you comfortable throughout the summer. Unless your air conditioner is simply not working at all, you may not realize that it is struggling until significant damage or wear has already occurred. The possibility of short cycling underscores the importance of sizing your air conditioner properly and getting regular maintenance once you have it installed. Air conditioning units should be selected based on the ideal size and output for a particular home.
This is difficult to do without expertise because there are so many factors involved, including:
- The amount of insulation in your home
- How many people live in your home
- The climate of your region
- The size and style of your home
- The efficiency of other systems within your home
In short, you cannot just calculate the square footage of your home and know how many tons your air conditioner should be. You may short or overestimate your needs, and both situations have problems.
Fixing Short Cycling
Now that you know the possible reasons why your AC keeps shutting off, it’s time to contact an HVAC technician. After you have an HVAC technician estimate your cooling needs and install a new air conditioner for you, it is absolutely crucial to get regular maintenance and repairs when you notice something is not right. Refrigerant leaks or a frozen evaporator coil might not be easy to see with an untrained eye. Experts know how to look for these issues and can often prevent them.
An air conditioner that is constantly short cycling is irritating and can make your summer much more uncomfortable. By getting the right size air conditioner and taking care of it properly, you can stop short cycling from costing you in money and comfort.