What to Do When Your Air Conditioner Starts, Then Stops After Only a Few Seconds

What to Do When Your Air Conditioner Starts, Then Stops After Only a Few Seconds

You can almost see the stress just reading this article. Whether on a sweltering humid summer day or a frigid winter evening, your air conditioner is a lifesaver. You kick on your air conditioner to cool down and make your home more comfortable. When you turn it on, the unit should run its course and end after a couple of minutes of keeping your house cool. However, if things go awry, you might find yourself stuck with an air conditioner that turns on for only a few seconds before shutting off again. 

Reducing the humidity in your home will reduce the risk of mold growth and help keep air conditioning bills lower in the long run. Keep reading to learn more about your ACs turning on and off and some advice to solve those issues. 

Reason Why Your Cooling System is Turning On and Off

When the temperature outside is hot, the last thing you want to do is spend your time sweating at home. Instead, you would wish for a cool and arid environment at home. An air conditioner is a must-have appliance in such humid summers. However, when the summer heat strikes and the temperature shoots up, you must keep your AC in check, so it does not go out of control. 

For this purpose, many people prefer installing timers on their AC to turn them on and off automatically at certain times of the day. It helps keep your power bill under check without compromising with rt levels. However, what if your AC keeps turning on and off even when you have put a timer on it? Let’s look at why your AC is turning on and off, as well as some solutions so you can try to get things running smoothly again.

Compressor Failure

The compressor is an essential part of an air conditioner and circulates refrigerant throughout the AC unit. If the compressor fails, the entire AC unit will shut down. Compressor failure is often caused by a loss of refrigerant, but it can also be caused by a problem with the electrical systems or a mechanical issue.

If your AC unit turns on and off repeatedly, it is likely because the compressor is failing. You should call a technician to come and diagnose the problem so that you can get it fixed before the AC unit stops working. They may also answer your question and guide you regarding the unit.

Dirty Air Filters

A dirty air filter is the most common cause of air conditioners turning on and off. When dirt and debris clog the air filter, it restricts airflow to the AC unit, causing the AC unit to work harder to circulate the air. As a result, the AC unit turns on and off more frequently to maintain a comfortable temperature.

If you suspect your AC unit is turning on and off due to a dirty air filter because of dust, the first step is to check the air filter and replace it if necessary. It’s also a good idea to clean the air filter housing every month to prevent anything that may build up dirt and debris. If you find that your AC unit is still turning on and off frequently, even after replacing the air filter, there may be a more severe issue at play. 

In this case, it’s best to contact someone who is a qualified AC repair technician for diagnosis and repair, since they also have the necessary tools needed for cleaning. 

Clogged Drain Line

If your AC turns on and off frequently, it’s likely because the drain line is clogged. The drain line is responsible for carrying away condensation from the AC unit, so when it’s clogged, the unit can’t get rid of the moisture properly.  To fix the problem, you’ll need to clear the drain line. You can do this with a wet/dry vacuum or a plunger. Once the line is clear, the AC should function properly.

Dirty Condenser Coils

The condenser coils on your air conditioner are responsible for dissipating heat. If the coils become dirty and have grime, they will not be able to dissipate heat effectively, and your air conditioner will have to work harder to cool your home. It will cause overheating of the coils and the air conditioner to turn off to protect itself. To prevent this, you should clean the coils on your air conditioner at least once a year.

Oversized Air Conditioner

An extensive system won’t have the proper refrigerant cycle. It will suffer several disadvantages, such as cooling your house too quickly and then shutting off shortly after it turns on. Unfortunately, your air conditioner will turn back on again sooner than it should if it turns off and on every 10 minutes. If your AC cycles on and off, an oversized air conditioner may be the culprit. These issues are not only annoying, but they might also cause more significant problems for your home, such as: 

  • Higher energy costs: An AC that turns on and off repeatedly consumes more energy.
  • More repairs: Not only does a short cooling cycle consume more energy, but it also puts more strain on the AC’s component.
  • A shorter lifespan: The lifespan will be quicker if you wear and tear your air conditioner.

Thermostat Issues

The reason your AC keeps cycling on and off may be a thermostat issue, so check your thermostat if it does. While the thermostat may seem like a tiny part of your air conditioning system, it controls your house’s temperature and must function correctly. The thermostat may signal the air conditioner to start and frequently stop if it is not detecting the temperature accurately and signaling misinformation. 

The thermostat might also lose power intermittently, causing it to turn off and on. It might come on and off due to losing battery power, so you must replace the batteries and restart the thermostat. If problems persist after attempting this solution, talk to an HVAC professional. The whole house’s temperature is controlled by this device, so it must work properly.

Bad Thermostat Placement

Your thermostat controls your AC, monitoring the air temperature and switching the system on and off as required. It may inaccurately record temperatures if it is located near a window and is exposed to direct sunlight, near a room that is always hotter than the rest of the house, such as the kitchen or washroom, beneath supply air vents, or receives direct airflow. Your thermostat may give inaccurate, poor readings, and your house may seem hotter or colder than it is. Put your thermostat in something more prominent, better location to remedy the problem.

Electrical Problems

Electrical issues are frequently the reason for short cycles. Your air conditioning system might have electrical problems due to the thermostat, electrical connections anywhere in the system, or circuit boards, in addition to issues with the electrical supply line or capacitor failure. An electrician with experience can assist. Diagnosing an electrical problem can be dangerous for even the most experienced homeowners and challenging.

Bad Run Capacitor

The running capacitor provides an AC’s initial burst of energy and continual current to keep the system functioning. An intermittent flow of electricity to the AC, causing it to turn on and off sporadically and then off after a brief period, maybe the result of a failing capacitor.

If your AC turns off after only a few seconds or after 30 seconds, your run capacitor is most likely to malfunction, and you should replace it. If this part breaks, other components will wear down prematurely due to increased wear and tear. Contact a local HVAC company if the AC capacitor isn’t functioning correctly and answer your questions.

Refrigerant Leak

If a leak in your AC system’s refrigerant has ruined your air conditioner’s efficiency, there may be a problem with the refrigerant level. Every time the AC system cycles, the refrigerant absorbs heat and cools the air in your home. Many people believe that refrigerant is consumed as part of the AC process, even though it is not. Refrigerant leaks are often the result of small holes in the system that allow the refrigerant to escape. The pressure drops when the compressor shuts down due to low refrigerant levels, and the compressor will restart. 

In turn, it causes a short cycle that causes a lot of wear and tear on the AC system, potentially leading to parts breaking down or total system failure. If you suspect a refrigerant leak, it’s essential to have a professional check it out as soon as possible as it can be damaging to your AC unit and your home.

Frozen Evaporator Coils

If your AC turns on and off frequently, it’s likely because the evaporator coils are frozen. It can happen for several reasons, such as if the air filter is dirty or the temperature outside is freezing. If the coils are frozen, they can’t absorb heat from the air, which is what they need to do to cool your home. The best way to fix this problem is to thaw the coil with a hair dryer or turn up the thermostat. 

You should also clean the air filter and ensure the temperature outside isn’t too cold. If the problem persists, call a professional. An outdoor AC unit may be suffering from ice buildup; if you have already checked your air filters and refrigerant leak, you should seek out and fix the leak immediately.


You would most likely need a technician to continue troubleshooting the issue in more depth, but a few potential causes have been suggested. A faulty thermostat or control board can cause the air conditioner to cycle on and off. However, this is unlikely and difficult to confirm without additional diagnostic testing.

A certified technician should perform an annual inspection of your air conditioning system. It will ensure that there’s nothing wrong with the AC unit and diagnose and fix any common problems associated with an HVAC system. A qualified technician can also advise you and give you info if your current setup is energy efficient or not.


How do I stop my air conditioner from cycling for a short cycle?

You can do a few things to stop your air conditioner from cycling for a short cycle. One is to ensure that the thermostat is set to the correct temperature. Another is to clean or replace the air filter. You should also check to see if the evaporator coils are frozen. If they are, you will need to thaw them out. Finally, you can try turning the air conditioner off for a few minutes to see if it will reset.

Can a faulty thermostat cause a short cycle?

A faulty thermostat can cause a short cycle when the system turns on and off more frequently than usual. Several things can cause it, including a dirty or damaged sensor, a loose wire, or a problem with the control panel. If you suspect that your thermostat is the cause of your short cycle, you should have it checked by a professional.

How do I know if my AC is a short cycle?

If your AC unit is a short cycle, it turns on and off more frequently than it should. It usually happens when the AC unit is too big for its cooling space, the thermostat is set incorrectly, or the AC unit is low on refrigerant. If your AC unit is short cycle, it’s essential to figure out the cause so you can fix it. Otherwise, your AC unit will continue to cycle on and off, which wastes energy and can cause damage to the unit.