AC Short Cycling: Why Is My AC System Turning On & Off?

Air Conditioning

Short cycling occurs when an air conditioner turns on and off too frequently, often due to thermostat issues, restricted airflow, or improper system sizing. This article explains how these problems reduce efficiency and increase wear on system components over time.

Causes of Air Conditioning Short Cycling Issues

Improperly Sized System

If your air conditioner turns on and off right away, it may be too powerful for the square footage of your house. The capacity of an air conditioning system can be measured by utilizing a metric called British Thermal Units (BTU’s). This metric refers to the total quantity of energy that is required to increase a single pound of water by 1 degree Fahrenheit. The BTU metric is utilized by professionals in the HVAC industry to quantify the total amount of heat energy in a home. The tonnage rating of a system refers to the total amount of heat an air conditioning system can eliminate from a house in a total of one hour. An air conditioner that features a rating of one ton is able to eliminate 12,000 BTUs of heat in a home per hour. If you have a smaller house, do not purchase an air conditioning system with a tonnage rating that is too high. An air conditioner that is too large will cool each room of your house too quickly. This will cause your system to push out too much cold air too quickly. To avoid AC short cycling issues, it’s important to purchase an air conditioner with a proper tonnage rating for the square footage of your home.

Refrigerant Leaks

The source of your air conditioner short cycling issues may be cracks or holes in your refrigerant lines. If a system loses too much refrigerant, it will be unable to properly remove excess heat from your home. Once the refrigerant level becomes too low, the air conditioning system will be required to work harder to maintain a comfortable temperature in your home. This will cause the air conditioner to become too warm. If the system becomes overheated, you may begin to notice an AC short cycling issue. We recommend calling a licensed HVAC contractor to patch the refrigerant leak and resolve the air conditioner short cycling problem. Do not attempt to use an air conditioner with a low amount of refrigerant. This will cause damage to internal components and can lead to expensive repairs.

Damaged Wiring

If your air conditioner was installed incorrectly by an unqualified contractor, the wiring may be damaged or faulty. Wiring issues may cause air conditioner short cycling problems and damage to your equipment and internal parts. Hire a licensed contractor to fix faulty wiring or a malfunctioning capacitor. Once the electrical components are fixed, your air conditioner should stop turning on and off rapidly. It will now produce normal cooling cycles that consist of 15 - 20 minutes.

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Ice on Evaporator Coils

The evaporator coils in a central air conditioning system are engineered to remove heat from the air in your house. If your evaporator coils become covered in frost, it will become harder for your system to remove excess humidity and warm air from the rooms in your home. This excess stress may cause your air conditioner to overheat, which will lead to short cycling problems. The only way to prevent frozen evaporator coils is to perform annual maintenance on your system.

Contaminated Air Filters

An air filter is designed to reduce the amount of dust and dirt in the air of your home. To avoid the issues caused by clogged air filters, it’s important to replace them at the end of their lifespan to prevent damage to your system. A clogged air filter will impede the flow of air in your home. As a result, the blower motor in your HVAC system will be required to work harder to push cold air throughout your house. This will cause excess stress on the compressor or blower motor of your air conditioner and cause short cycling problems.

Location of Thermostat

The thermostat in your house should be installed in a central location away from sunlight and supply vents. If the thermostat is installed near a vent, it will detect the incoming cold air from the HVAC system. This will cause it to believe it’s too cold in the house. To combat the cold temperatures, the thermostat will send a command to the air conditioner to stop its cooling cycle before the entire house reaches the desired temperature. Since the sensor on the thermostat is not accurately detecting the temperature of your house, it will cause AC short cycling issues. If you need to move a thermostat in your home, we recommend talking with a professional HVAC technician.

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Air Conditioning Services in Pennsylvania

If your air conditioner is short cycling, we recommend scheduling an air conditioner repair, tune-up, replacement, and installation appointment with our team in Pennsylvania. We provide heating and cooling services in locations such as Broomall, Coatesville, West Chester, and Conshohocken. From furnaces, central air conditioners, to heat pumps, there is no problem too large for our team to handle. Give us a call by phone at (484) 206-8594 or book an appointment online to receive assistance.