Short cycling occurs when your air conditioner shuts down before effectively cooling your home, sometimes starting again quickly. Not only does this leave your home uncomfortable, but it also increases your energy consumption and the wear on your system. Consider these 10 common reasons your air conditioner may short cycle and what you can do to prevent it.
1. Dirty Air Filter
A dirty air filter is a leading cause of many AC problems, including short cycling. When a filter is neglected long enough, it can become clogged and restrict the airflow into the system. For an air conditioner, this can cause the evaporator coil to get too cold because of insufficient warm air flowing through the system, causing the system to shut down.
Preventing dirty filters starts with routinely checking and replacing the filter. The 1- and 2-inch filters commonly need replacing every 30 to 90 days. If your system uses 3- to 6-inch filters, they may last from several months up to as long as a year. Regardless of you filter’s size, check it every month, and gently vacuum it to remove loose contaminants and help extend its lifespan.
2. Faulty Compressor
Aside from the circulating fan motor, the compressor is the major component that runs your air conditioner. This component regulates the system’s refrigerant pressure through the high-pressure side of the system. When the compressor malfunctions, it may not build sufficient pressure for the system to expel the heat it absorbed inside your home.
Aside from short cycling, signs you may have a faulty compressor include:
- Loud noises from the outdoor unit
- Weak or no supply airflow
- Tripping circuit breaker
- Insufficiently cool air
3. Refrigerant Leak
The compressor can’t build the proper pressure in the system when there’s insufficient refrigerant. Further, low refrigerant, caused by a leak, can lead to freezes throughout the system, usually near the source of the leak. These freezes happen because the refrigerant is expanding too quickly, which allows it to get cold and freeze moisture condensing out of the air and onto parts of the system.
4. Thermostat Problems
Your thermostat is your air conditioner’s brain, so if there’s a problem, it can throw off how the whole thing works. Common problems include age and faulty sensors.
Thermostats have an expected lifespan of about 10 to 15 years. After this time, the internal sensors registering temperature may not work as effectively, causing it to register temperatures that are too cool. Also, those sensors can become faulty prematurely, which can also lead to short cycling.
5. Dirty Refrigerant Coils
Your air conditioner has two refrigerant coils, the outdoor condensing coil and the indoor evaporator coil. Both collect dust and dirt, which can slowly form a coating on the coil, inhibiting the system from transferring heat as well as it should.
Regardless of which coil is dirty, it can cause the system’s refrigerant to become incorrectly hot or cold. This makes the system shut down until the refrigerant temperature stabilizes, allowing it to restart.
6. Electrical Issues
An air conditioner is a massive electrical appliance with many connections and several types of components. It may experience electrical issues, especially if you neglect routine maintenance.
As the system runs, it vibrates, loosening electrical connections. These connections increase electrical resistance and can create an unstable circuit. The result may include what appears as short cycling, with the system shutting down in the middle of a cooling cycle.
7. Airflow Restrictions
As discussed previously, your system depends on airflow, and there are many other restrictions beyond the filter. The outside condensing coil can come blocked with grass, weeds, leaves, flowers and many other things. Inside your home, airflow may decrease when you close vents or they become blocked. Regardless of the cause, airflow restrictions of all kinds reduce efficiency and may cause short cycling.
8. Faulty Low-Pressure Control Switch
One of the safety mechanisms included in your air conditioner is the low-pressure control switch. This monitors the pressure on the low side of the system and shuts it down when it gets too low. Like any other switch, it can fail and erroneously register low pressure, shutting the system down. Fortunately, this switch is one of the components a technician can replace if it’s not yet time for a new air conditioner.
9. Bad Thermostat Location
Where you place your thermostat is crucial for it to perform well. The recommended location is on an interior wall that’s out of direct sunlight and not in the flow of a supply vent. When it’s too close to a supply vent, it may register the set temperature before the system has had a chance to effectively circulate conditioned air. This results in shutting down quickly, only to restart again once the temperature equalizes.
10. Oversized Air Conditioner
Air conditioners come in different sizes based on the cooling capacity of the system, and they are measured in British thermal units (BTU) or tons. While more cooling capacity may appear to be a better deal, it can inhibit the system’s effective cooling if it’s too much. An oversized unit will get too cold quickly, causing the system to shut down. Larger systems use more power, and an oversized system will start more frequently. All these factors combine to leave your home warm while you receive higher energy bills and pay more for the system.
Preventing AC Short Cycling
Beyond replacing your air filter, one of the best ways to prevent short cycling is to get routine AC maintenance. This is commonly done once a year, preferably in the spring before you start to rely on your cooling system. While maintenance may not prevent all these problems, it can help to identify them before you start experiencing short cycling.
During a maintenance visit, a technician will clean your system, including the evaporator and condensing coils and the circulating fan wheel, helping to prevent airflow restrictions. They’ll also run extensive tests on the system, including checking the refrigerant level, the compressor function and many electrical control components. Then, they’ll inspect and tighten all electrical connections and mounting hardware to minimize the chances of unstable circuits or excessive vibration.
You need to fix your air conditioner as soon as you know there’s a problem whether it’s something you notice or something the technician finds during maintenance. The longer small problems go unresolved, the bigger they’ll become and the more likely they’ll make your system short cycle.
For over 30 years, property owners in Dallas, GA and the surrounding area have trusted Precision Heating & Air to keep their homes comfortable. Our experienced team members pride themselves on providing dependable heating and AC repair, maintenance, installation, indoor air quality solutions, and water heater installation, maintenance and repair.
If your air conditioner is short cycling, call Precision Heating & Air today to schedule a repair visit from one of our NATE-certified technicians. Our Precision MVP Memberships will ensure you get the maintenance you need!
