Why Does My Air Conditioner Turn Off by Itself?
July 20, 2023
You don’t have to live in Corpus Christi, TX, for very long to understand the importance of a functioning air conditioner, especially during the hot and humid summer months. That’s why it can be frustrating when your air conditioner turns off on its own, leaving you scrambling for a solution.
There are a few possible reasons why your air conditioner is turning off by itself—even if your home hasn’t been cooled yet. The reasons range from merely annoying to larger problems that require the help of a professional.
Here’s why your AC may flip off right when you need it most.
7 Reasons Your AC Turns Off on Its Own
Incorrect Thermostat Setting
If your thermostat isn’t set correctly, your air conditioner could be acting oddly. Is it set to the desired temperature? Verify that it’s in cooling mode and not "auto" mode, as this may cause the AC to turn on, then off too frequently. Adjust the settings accordingly to see if it resolves the issue.
If your home’s AC thermostat keeps turning off and simple fixes don’t work, it may be broken.
Broken Thermostat
Do you notice your AC keeps turning off even though the thermostat says it's on? A malfunctioning or faulty AC thermostat can cause your air conditioner to turn off by itself. It may switch quickly between off and on in short intervals, called “short cycling.” If the thermostat is not accurately sensing the room temperature, it may mistakenly signal the cooling to shut off prematurely.
To see if this is the problem, check the thermostat's battery and test to see if your HVAC is working in other modes (such as auto or even heat). This is also a good time to check to see if the connections are still intact and that your thermostat isn’t dusty or dirty inside, which can also cause it to malfunction. If the problem persists and other modes aren’t working as they should, it might be time for a new thermostat.
Dirty Air Filter
Clogged, dirty air filters restrict airflow and can lead to overheating and automatic shut-off of the air conditioner. Clean or replace the air filter as recommended by the manufacturer: usually every 90 days, or more often if you have pets. This simple maintenance task can sometimes fix unexpected shutdowns.
Refrigerant Issue
Insufficient refrigerant in the refrigerant lines can cause your air conditioner to shut off as a protective measure. Low refrigerant can lead to inadequate cooling and strain the compressor, triggering safety mechanisms that shut down the AC. If your air conditioner turns off by itself, accompanied by a sweet chemical smell or ice on the outdoor unit, it’s likely a refrigerant leak. You’ll need to contact an HVAC professional to repair refrigerant-related issues.
Electrical Problems
Electrical issues, such as tripped circuit breakers, can interrupt the power supply to your air conditioner, causing it to turn off suddenly. Check your circuit breaker panel to ensure all relevant switches are in the "on" position. If breakers continue to trip when you run your AC, your best bet is to contact an electrician to inspect the electrical system and make any necessary repairs.
Overheating Outdoor Unit
If the air conditioner's condenser unit (located outside your home) becomes overheated due to blocked airflow or mechanical issues, it may automatically shut off to prevent damage. Ensure the condenser unit is clear of any debris, vegetation, or obstructions. Don’t cover the unit during the summer, even in an attempt to shield it from the sun; this may just make the airflow problem worse. If the issue persists after you’ve cleared the area around the unit, reach out to an HVAC technician.
Faulty AC Compressor
A malfunctioning compressor (also part of the outdoor unit) can cause the air conditioner to shut off intermittently. The compressor is responsible for pressurizing the refrigerant and circulating it through the system. An HVAC technician can diagnose and repair compressor-related problems.
Why Does My AC Turn Off by Itself? DIY Solutions vs. Professional Repairs
In general, unless it’s a straightforward issue such as bad thermostat batteries, a tripped circuit breaker, or a clogged air filter, you’ll likely need to call in a professional.