This article was co-authored by Victor Belavus and by wikiHow staff writer, Eric McClure. Victor Belavus is an Air Conditioning Specialist and the Owner of 212 HVAC, an air condition repair and installation company based in Brooklyn, New York. In addition to HVAC and air conditioning units, Victor also specializes in furnace repair and air duct cleaning. He has over 10 years of experience working with HVAC systems.
There are 16 references cited in this article, which can be found at the bottom of the page.
This article has been viewed 753,461 times.
Few things in life are as irritating as your air conditioner acting up on a hot summer day. But before you pick that phone up to spend hard-earned money on a potentially-unnecessary service call, there are a few basic things you should do to see if you can solve or identify the problem yourself. Keep in mind, you will not be able to solve every potential problem. It’s not safe to mess around with your AC’s electrical wiring, and opening the AC system up may just make the problem worse, so don’t hesitate to call for help if you need it.
Steps
What do I check if my air conditioner shuts off by itself?
-
1Check the circuit breaker to see if it's been tripped. If you’ve got too many electronics plugged in and running, you may have overloaded the circuit. This is especially likely if you’ve got a bunch of fans running during a hot summer day. Check your fuse box to see if the circuit breaker is set in the off position and flip it back on.[1]
- If everything else shut down at the same time, you may simply be dealing with a power outage.
-
2Check the auto settings on your thermostat. If your air conditioner keeps kicking on and off in intervals, look at your thermostat to see if it’s set to “auto” or “automatic.” If it is, this is why your AC keeps shutting off. When it’s set to auto, the AC system will only turn on after the temperature has risen past the number on your thermostat.[2]
- It’s much more efficient to keep the thermostat set to “auto” when you’re heating or cooling your home. Still, if it isn’t warm or cool enough for you, feel free to adjust the thermostat!
My AC turns on but the airflow is messed up. What do I do?
-
1Change the air filter. Your filter needs to be replaced every 3 months or so. During the hot season, you may need to replace it every month. If you’ve got a problem with your AC unit and you haven’t replaced the filter in a while, do that first. If the problem resolves itself, you don’t need to call anyone. If the problem persists, you’ll probably need to call an HVAC technician.[4]
- On a central AC system, the filter is usually located in the duct on the return line, or on the furnace. In a ductless system, there’s a reusable filter on the condenser outside. For a window unit, the filter is usually behind the grates on the front.[5]
-
2Check your vents and ducts for blockages. If there are any obstructions in front of the vents or ducts, this could disrupt your system’s ability to function correctly. Take a stroll around your home and make sure all of your vents and ducts are clear and open. If necessary, rearrange your furniture to make sure that everything is open.[6]
- If there is any debris outside around your condenser unit, clear it away. This can occasionally be the source of the problem.
What do I check if my AC turns on but isn't blowing cool air?
-
1See if the air filter is dirty and change it out. Swapping out your air filter may help. A dirty filter can mess with an AC unit’s ability to blow out cool air, so try this first to see the problem resolves itself. If you have a reusable filter, clean it thoroughly before replacing it.[7]
-
2Inspect the refrigerant line. On a central or split system, go outside and look for the largest pipe leading into your AC’s condenser. If your AC is on and this pipe has ice on it, shut your system off and give this pipe time to thaw before turning it back on. If this problem occurs again, you may be running low on refrigerant.[8]
-
3Clean off the condenser coil on the outside unit. Head outside and remove any garbage surrounding the condenser. If anything is stuck in the fins, remove it by hand or with a broom. Then, grab a hose and gently spray down your condenser unit. Keep rinsing it until the water runs clear. Dirty coils can occasionally disrupt the airflow and make it feel like your vents are blowing out warm air.[9]
- You can clean the coils on a window unit as well, but you’ll need to take it outside to do this.
Which issues are too dangerous to troubleshoot myself?
-
1Anything involving leaks or opening the AC unit up is risky. While it’s perfectly fine to take a look to try and find a problem, you really shouldn’t mess around with your AC unit too much. You won’t be able to diagnose anything going on inside of the condenser or furnace, and opening them up may void your warranty or make things worse.[12]
- Freon and other refrigerants can be toxic, so don’t mess around with any leaks or fluids in your AC system.[13]
-
2Messing with the electrical components is especially dangerous. AC systems are typically high voltage, and it’s dangerous to toy around or touch any live connections.[14] There are a variety of problems that look like a blown fuse, but aren’t. On top of that, you won’t be able to fix any of these problems yourself, so it’s just going to be more efficient and safe to have a professional take a look.[15]
- You can theoretically check the cartridge fuses on an AC system with a multimeter, but it won’t necessarily tell you much and it’s dangerous. A professional will be able to check the fuses in 30 seconds anyway, so there isn’t a particularly good reason to check them yourself.
Expert Q&A
Did you know you can get expert answers for this article?
Unlock expert answers by supporting wikiHow
-
QuestionIf I need to get my AC serviced, how should I prepare for the AC technician?
Victor BelavusVictor Belavus is an Air Conditioning Specialist and the Owner of 212 HVAC, an air condition repair and installation company based in Brooklyn, New York. In addition to HVAC and air conditioning units, Victor also specializes in furnace repair and air duct cleaning. He has over 10 years of experience working with HVAC systems.
Air Conditioning SpecialistTry to remember your service history and let the tech know if there are any pre-existing conditions with the system. Also, make sure you have provided adequate access to both your indoor and outdoor units.
Support wikiHow by unlocking this expert answer.
References
- ↑ https://www.familyhandyman.com/list/12-things-to-check-before-you-call-an-hvac-tech/
- ↑ http://www.daikinac.com/content/assets/DOC/CTXSWallOperationManual.pdf
- ↑ https://youtu.be/z-XeWRzX86g?t=32
- ↑ https://time.com/4408512/air-conditioning-mistakes/
- ↑ https://www.bobvila.com/articles/how-to-clean-an-ac-filter/
- ↑ https://www.consumerreports.org/air-conditioners/troubleshooting-air-conditioner-problems/
- ↑ https://time.com/4408512/air-conditioning-mistakes/
- ↑ https://youtu.be/beVRELr8Oak?t=30
- ↑ https://www.bobvila.com/articles/how-to-clean-ac-coils/
- ↑ https://www.stansac.com/reset-your-thermostat/
- ↑ https://time.com/4408512/air-conditioning-mistakes/
- ↑ https://www.energy.gov/energysaver/maintaining-your-air-conditioner
- ↑ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5529683/
- ↑ https://americanhomewater.com/ac-blows-a-fuse/
- ↑ https://www.energy.gov/energysaver/common-air-conditioner-problems
- ↑ https://www.consumerreports.org/window-air-conditioners/when-to-get-a-new-window-air-conditioner/
- ↑ https://www.thisoldhouse.com/heating-cooling/21018989/read-this-before-you-buy-ductless-ac
- ↑ https://www.bobvila.com/articles/how-long-does-an-air-conditioner-last/
About This Article
To check your air conditioner before calling for service, troubleshoot by noticing if it isn’t running at all or if it just isn’t blowing cool air. If it isn’t working, check to make sure the unit is plugged in and the thermostat is set to cool. If those elements are set, check your circuit breakers and fuses to make sure they are in place and turned on. If your unit isn’t blowing cool air, check the fan blower belt for damage or breakage and replace it if need be. Additionally, clean the coils and filters of dust and debris to keep the unit working properly. For preventative maintenance tips, like how to wash condenser coils, read on!
