Air Conditioner Starts Then Stops After Only a Few Seconds – 8 Effective Solutions

It’s a hot summer day. You go home wanting to relax with some cool air. First, you turn down your thermostat, but then the air conditioner starts then stops after only a few seconds. Uh-oh… What do you do now?

If your air conditioning unit starts and then stops after only a few seconds, it could be a thermostat issue, a dirty air filter, dirty condenser coils, a problematic capacitator, an AC unit too big for your space, refrigerant leaks, poor thermostat placement, or general electric issues. 

Homeowners, read on below to learn about each of these eight potential causes, as well as how to address each one to get your AC unit working properly as soon as possible. 

8 reasons your air conditioner starts then stops after only a few seconds

Find yourself asking the question, “Why does my ac compressor shut off after 2-3 minutes?” One common problem with air conditioning units is a phenomenon known as “short cycling.” This occurs when an air conditioning system starts producing cool air, then stops after only a few seconds of output.

Short cycling can be a confusing problem to address because of the variety of potential causes that can be associated with this issue. 

If you’re wondering how to fix short-cycling air conditioners, make sure to consider all of the following potential causes before attempting to fix your machine. 

Thermostat issues

The thermostat is one of the most critical components of any AC unit. That’s because it handles the cooling of your house. The thermostat reads the room temperature and then responds accordingly to start or stop the AC. This could be one reason why an air conditioner turns off after 30 seconds.

Therefore, if the thermostat has a problem, it can dramatically affect the output of the unit as a whole. Specifically, a faulty thermostat has been known to cause the air conditioner to start and then stop after some time — a phenomenon known as short cycling.

If this is occurring with your AC unit, it might be because after the AC starts, the thermostat has a reading error and detects an okay level of coolness, which may cause it to immediately shut back off. 

air Conditioner Starts Then Stops After Only a Few Seconds

How to fix it

The solution to this riddle could be something as simple as the thermostat having defective batteries. Changing them would be a quick fix for the problem. However, if it persists, you may need to call an HVAC specialist to locate the issue. But before you do that, read the remainder of this list to rule out any of these other potential causes. 

Read AlsoThe Room Temperature Doesn’t Match the Thermostat Setting – What to Do

A Dirty Air Filter

Air filters are prone to getting dirty as they work. That’s because they’re constantly removing particles and dust from the air they take in. Therefore, over time, the dirt can accumulate and start causing a short cooling cycle, overheating, and other ac problems.

air Conditioner Starts Then Stops After Only a Few Seconds

How to fix it

To solve this issue, examine the filter for dirt, then remove and clean it with a hand brush. Opening up the AC isn’t that complicated. After removing all the screws that hold the cover onto the unit, you should be able to pull out the filter.

Take the filter outside and clean it with a hand brush. Be careful not to track dust all over the house. In some cases, you might want to spray the filter down with a hose and let it try. 

Dirty Condenser Coils

It isn’t only dirty air filters that might cause issues in an air conditioning unit. Dirty condenser coils are a major culprit in short cycling. If the condenser coils haven’t received cleaning for some time, they might cause the inner parts of the AC to overheat and short cycle. That’s why you should periodically clean all the parts of the unit, including the condenser coils.

air Conditioner Starts Then Stops After Only a Few Seconds

How to fix it

To clean out the condenser coils, simply take a garden hose to the outside unit. Spray the coils off thoroughly. This should take a few minutes to do properly. If you don’t feel comfortable cleaning them yourself, then get an HVAC specialist that will do routine maintenance for you.

A Problematic Capacitor

The capacitors enable the AC unit to turn on and off with the energy it provides. Therefore, a problem with the capacitor will affect the working of the AC unit. A poorly run capacitor will make your unit turn on and off intermittently.

That’s because it won’t transmit enough energy to the unit to keep it on for long if it is malfunctioning. The capacitor should enable the Ac unit to stay on for as long as you need it.

How to fix it

For the most part, any problem with the capacitor will require the help of an HVAC professional. If you decide to try it on your own, you may need to consult the manual for your AC Unit. The video below will provide some more information on this task. 

Your Air Conditioner Is Too Large

If you used to have a smaller size AC that you replaced with a bigger one when the issues started, that could be the problem. The larger unit might have issues with this refrigeration cycle that makes it suddenly turn off after turning it on.

The unit could work so fast with a defective refrigeration cycle and then turn itself off after working only for a short time.

air Conditioner Starts Then Stops After Only a Few Seconds

How to fix it

Unfortunately, this problem doesn’t have a simple fix. In this case, you may have to purchase an AC unit that better fits the system you already have in place.

Refrigerant Leaks

The Refrigerant absorbs heat so that the thermostat responds to the heat changes in the environment. Therefore, whenever it has an issue or is leaking, it won’t be able to do its job properly, which might cause the AC to have a short cycle.

The short cycle might last between 10 and 15 minutes. Refrigerant leaks also lead to low pressure in the AC unit and a faulty compressor. Your AC will start and then shut off after a few seconds or minutes.

air Conditioner Starts Then Stops After Only a Few Seconds

How to fix it

This is another problem that may require the services of an HVAC professional. Generally, a refrigerant leak will require a specially sealed patch to stop the substance from seeping out of your unit and a refrigerant charge.

If the leak is small enough, you might be able to create a temporary solution by using duct tape or a special type of sealant. But in most cases, this is a fix that will require professional equipment and experience.

Wrong Thermostat Placement

This may seem overly simplistic, but short cycling could be caused by a misplaced thermostat. If, for example, your thermostat is next to the window, every cool breeze could hit it on the way in, lowering the temperatures it reads.

Such placement will mess with the thermostat and transmit the wrong signal to the AC, causing it to short cycle. That’s because while you’d expect the AC unit to cool your house, the thermostat reads the cool breeze as the room temperature and turns off the unit.

air Conditioner Starts Then Stops After Only a Few Seconds

How to fix it

You will be able to solve this merely by placing your AC in a more centrally located spot and away from windows or any other openings that could impact temperature and humidity readings.

Electrical issues

Electrical issues are another primary culprit behind a malfunction in most AC units. If you are facing issues with your AC, even if it’s well maintained, then the reason could be electrical problems.

Electrical issues are mainly because of defective wiring in the unit and might cause it to short cycle.

How to fix it

If you suspect this problem, reach out to a professional for help.


Hopefully, this article has helped solve your AC problems and you won’t have to deal with humid, stuffy, stiffling, muggy, unpleasantly warm, or downright oppressive conditions in your home.

If the air conditioner starts and then stops after only a few seconds, you should now have a better idea of where to start. Several issues would cause an air conditioner to short cycles. The solutions we have given here should help you solve most of them quite easily.

Always remember to contact an HVAC professional for help with the more complicated issues.

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