My Air Conditioner Is Not Staying On
An air conditioner will naturally cycle on and off to control the temperature of your home, but if cycling on and off happens too quickly or the air conditioner shuts off before your home is comfortable, there may be something wrong. This condition is often known as short cycling, and not only can it reduce your comfort, but it can also lead to costly repairs and higher utility costs.
What Is Short Cycling?
Normally, an air conditioner will run for about 10 to 15 minutes, cool the home down, then shut off for a while before repeating the process. If your air conditioner only stays on for a few minutes at a time and shuts off before it has a chance to cool your home, this is called short cycling. The issue is relativity common and can have a range of causes, from a clogged air filter to an oversized system. It can be detrimental to the efficiency, performance, and lifespan of your air conditioning system, and it should be addressed as quickly as possible.
What Causes Short Cycling in Air Conditioners?
The most common causes of an air conditioner cycling on and off rapidly include:
- Thermostat malfunctions – A damaged thermostat or a digital thermostat with low batteries may cause a wide range of problems, including short cycling. Also, a thermostat placed in a poor location may cause rapid cycling, such as a thermostat that is near a duct return, in a sunny location, or too close to a hot appliance. The thermostat will heat up quickly, turning the system on, then shut it off as the temperature drops rapidly.
- Control board or electrical problems – Faulty control boards, sensors, relays, fuses, or start capacitors may cause any number of problems with your air conditioner, though sometimes a simple reset of the power will get the system running properly again.
- Clogged air filter or duct obstructions – If the airflow over the evaporator is not sufficient to vaporize the refrigerant, the compressor may overheat, shutting the air conditioner off prematurely. Air flow problems can usually be traced to a dirty air filter, a blocked air duct register, or debris in the ductwork.
- Dirty coils or frozen evaporator – A dirty evaporator or dirty condenser coils can impede heat transfer of the air conditioning system, allowing it to overheat and shut down. In some cases, the evaporator may start to ice up due to a combination of dirty coils and poor airflow, and the system will shut off until it is properly thawed.
- Low refrigerant – Refrigerant leaks or an insufficient refrigerant charge can cause erratic and unstable pressures in the compressor. This can cause a safety switch to trip, shutting the system down before your home has cooled completely.
- Oversized air conditioner – If your system has always short cycled, or you have a new air conditioner that started short cycling right away, it may be too large for your home. The air conditioner will cool the home rapidly, shut itself off, and repeat the process. Though it is operating relatively normally, an oversized system can lead to reduced comfort as it cannot dehumidify or filter the air properly in a cycle that is too short. Also, the added stress of starting and stopping the compressor will cause premature wear and higher utility costs.
If you cannot fix the short cycling problem by resetting the breakers, changing the thermostat batteries, or replacing the air filter, it may be necessary to call an HVAC professional.
Air Conditioner Repair in Dallas & Plano, TX
When you need fast service and professional air conditioning repairs, trust our team at Total Air & Heat. We have been serving the Dallas area since 1957, and our technicians will get to the bottom of your AC problems quickly.