6 Possible Reasons Why Your AC Unit Is Short Cycling

October 18, 2022
AC unit in Seattle, WA

Air conditioning problems are always frustrating. And when the Seattle, WA summer is in full force, you most certainly need your AC unit to be doing its job effectively. However, if your cooling system is short cycling, it can affect your comfort, energy bills, and the overall health of the appliance. When an air conditioner is short cycling, it will typically only run for a few minutes at a time before shutting off prematurely. As a result, it takes significantly longer for your home to reach your preferred temperature, which uses more electricity and puts extra wear and tear on the AC unit. If you’re dealing with this annoying issue in your home, there are several potential reasons why it could be happening.

1. Dirty Air Filter

One of the most common reasons why an AC unit may short cycle is that its air filter is dirty or clogged. Your AC air filter has the important duty of trapping airborne contaminants before they can get cycled into the system and around your home. However, these filters only have so much space to catch particles before they become clogged. When that happens, it can start to cause a variety of problems if you don’t replace the filter with a new, clean one.

In addition to worsening the performance and efficiency of your air conditioner, a clogged filter can cause the system to short cycle. Usually, this happens because the airflow of the appliance becomes restricted, which results in the unit overheating. When your AC unit overheats, it will typically shut off on its own as a safety precaution, causing its cycle to be cut short. So, if your air conditioner is short cycling, checking the status of its filter is always a good first troubleshooting step. If it appears to be dirty, switch it out with a new filter to see if that solves your problem. And remember, it’s important to replace your HVAC air filters every month or two to keep the system operating smoothly.

2. Leaking Refrigerant

Another possible cause of your AC short cycling is that the system is low on refrigerant. Refrigerant is a chemical that is extremely important to your air conditioner’s cooling process. If it is leaking from somewhere, the unit may not have a sufficient amount of it to work properly. And if your cooling system doesn’t have enough refrigerant, it needs to work much harder to effectively control your home’s climate. All of that extra strain can result in a variety of equipment problems and malfunctions, with one possibility being short cycling.

If your air conditioner is leaking refrigerant, it’s unlikely that you’ll be able to solve the issue yourself. You should not attempt to do so. However, if you schedule an appointment with our team at Brennan Heating & Air Conditioning, one of our expert technicians will give your AC unit a thorough inspection. If there’s a refrigerant leak, they’ll find the source and get it repaired for you.

3. Thermostat Issue

In some cases, an air conditioner’s short cycling can be caused by something as simple as a thermostat issue. For example, if your thermostat is not calibrated correctly, it may have trouble accurately gauging your home’s temperature. As a result, your AC unit may turn on and off at seemingly random times. Sometimes, this can take the form of the system starting up in an effort to reach the correct temperature, and then rapidly shutting down because the thermostat thinks it has achieved its goal. It could also be that the thermostat is poorly placed within your household. If the thermostat is in a spot where it receives direct sunlight, it can mess with its temperature reading. This can potentially result in your cooling system starting up and turning off frequently.

To avoid these issues, you should make sure your thermostat is placed near the center of your home and away from any doorways or windows. Ideally, it should be in an area where it will experience temperatures as close to your dwelling’s average climate as possible. And if you suspect that your thermostat is malfunctioning, consider replacing it or having your local HVAC technicians inspect it.

4. Frozen Evaporator Coil

Another important component in your air conditioner’s cooling process is the evaporator coil. After the compressor moves the cold refrigerant into this coil, the warm air is blown over it. This causes the heat to be removed and cools down the air before it is distributed around your home. However, there are a variety of issues that can result in the evaporator coil becoming frozen. And when your air conditioner has a frozen evaporator coil, it can lead to the system overheating. Overheating can directly cause short cycling.

If you believe that your AC has a frozen evaporator coil, you can attempt to fix it yourself by shutting the system off completely for 24 hours. This should allow the coil to defrost. If that doesn’t work, and the coil simply freezes again, you should give us a call at Brennan Heating & Air Conditioning. Our team will determine why the issue is occurring and find an effective fix.

5. Incorrectly Sized Air Conditioner

It’s very possible that your AC unit is short cycling because it is either too small or too large for your household. If you did not have dependable HVAC professionals properly evaluate your home’s cooling needs before installing the system, it may not be the right size for your living space. If the unit is too large, then it will likely cool your home down too quickly, causing it to frequently shut off before it completes its cooling cycles. If it is too small, then it probably will not be powerful enough to do its job. The unit will likely overheat and shut itself off prematurely. Either way, it’s an issue that you will want to address. At Brennan Heating & Air Conditioning, we can inspect your air conditioner as well as your household situation to determine if the unit is incorrectly sized.

6. Electrical Issues

Although most homeowners don’t consider them often, electrical issues can be the source of many common air conditioner problems. Short cycling is certainly not an exception. If something is going wrong with your AC unit’s electrical system, it could be causing the appliance to randomly shut off while it’s still in the middle of a cooling cycle. In some cases, it may be that one of the system’s connections has become loose, resulting in unreliable connectivity. It could also be that one of those connections is corroded. Whatever the specific issue may be, it’s important that you don’t try to solve a potential electrical problem on your own. If you are not experienced, you could potentially put your safety at risk. Instead, let your trusted local HVAC technicians inspect your AC unit’s electrical connections to determine what’s going on.

At Brennan Heating & Air Conditioning, we’ve been faithfully serving the greater Seattle area since 1987. We’re committed to providing excellent customer service and high-quality work on every project we do. Our top-notch offerings include heating services, air conditioning services, air duct cleaning, electrical services, and water heater repairs. Contact Brennan Heating & Air Conditioning today to schedule an appointment!

Brennan Heating & Cooling icon