How do I fix my AC that keeps turning off?

Author: Dr. Carmela Bernier  |  Last update: Thursday, December 25, 2025

Clean the condenser coils: Dirty condenser coils can cause the AC unit to overheat and turn off by itself. Use a soft brush or vacuum cleaner to clean the coils regularly. Call a professional: If the issue persists, it may be time to call a professional HVAC technician to diagnose and fix the problem.

Why is my air conditioner shutting off by itself?

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.

Why does my AC stop working after 5 minutes?

One common culprit is a malfunctioning thermostat. If the thermostat is not functioning correctly, it might be misreading the temperature in your space, causing the compressor to shut off prematurely. Another possibility is a clogged air filter.

Why does my air conditioner run for a minute then shut off?

Your air filter is dirty or clogged. When the filter is clogged, the system cannot pull enough fresh air through. As a result, your system may overheat, which will cause it to kick off before the cycle ends. The evaporator coils have frozen.

How do I stop my AC from short cycling?

How To Stop and Prevent Short-Cycling
  1. Check your air filter. Believe it or not, a clogged air filter can cause a wide variety of air conditioning issues. ...
  2. Check your thermostat placement. ...
  3. Check your air conditioner's refrigerant levels. ...
  4. Replace the low-pressure control switch. ...
  5. Check the compressor.

9 Reasons Why Your Air Conditioner Starts Then Stops Quickly

How to tell if AC is short cycling?

The system will turn off prematurely and then quickly turn back on in an attempt to reach the set temperature. The thermostat will incorrectly tell the unit that the set temperature was reached or vice versa. A miscalibrated thermostat puts lots of strain on the HVAC system and can be a difficult problem to notice.

How much does it cost to fix a short cycling AC unit?

Central AC Short Cycling

Homeowners spend between $75 and $600 to deal with short cycling issues in their central AC systems.

How to reset an air conditioner?

Reset the AC Using the Isolation Switch

The isolation switch looks like an ordinary light switch with a knob. Once you locate it, turn the knob to the off position and leave it for at least 30 minutes up to an hour. This will allow the electrically operated components in the AC to reset.

How to know if AC is low on refrigerant?

Warning Signs of Low Refrigerant in Your AC or Heat Pump
  1. Weak Airflow or Warm Air Blowing from Vents. ...
  2. Poor Cooling Performance. ...
  3. Constant Cycling On and Off. ...
  4. Ice Buildup on Refrigerant Lines or Evaporator Coil. ...
  5. Hissing or Bubbling Noises.

Why does my air conditioner turn off after 5 seconds?

Your AC Unit Is Damaged

For example, if the AC compressor cycles on and off every five seconds or so, the condenser coils could be dirty or clogged with debris.

Why does my AC keep turning on and off every 10 seconds?

There are 3 common causes for short cycling:

Low refrigerant/Freon. Oversized air conditioner. Poorly located thermostat.

How to clean air conditioner condenser coils?

These are the steps our technicians take to make your AC's outdoor coil clean and sparkly:
  1. Turn off power to the unit. ...
  2. Check the refrigerant pressure. ...
  3. Remove the outer casing. ...
  4. Rinse the coil down with water. ...
  5. Spray the coil with cleaning chemicals. ...
  6. Re-rinse the coil with water.

How do you stop your AC from turning off?

Change the air filters: Dirty air filters can cause the AC unit to overheat and turn off by itself. Changing the air filters regularly can help prevent this issue. Check the thermostat: Make sure the thermostat is calibrated correctly and set up properly for your home's climate conditions.

How to tell if a thermostat is bad?

A bad thermostat can be detected when your AC or furnace is not turning on, your HVAC systems are not turning off, the thermostat not responding, your HVAC system is short-cycling, the room temperature not matching the temperature displayed on the thermostat, and the programmed setting resetting themselves.

How to check refrigerant level in AC?

Steps for Checking Refrigerant Levels
  1. Turn Off the AC and Remove the Cover. Turn off the AC unit and remove the cover to access the refrigerant level gauge or gauges.
  2. Locate and Remove the Access Panel. ...
  3. Attach Refrigerant Pressure Gauges. ...
  4. Interpret Pressure Levels. ...
  5. Add Refrigerant (if Necessary)

How do I know if my AC needs recharging?

Take note of the strength of the air that blows out of your AC vents. If you notice weak or low airflow, this could likely mean you're running low on refrigerant. Be sure to rule out any other potential causes before recharging your refrigerant.

Can AC lose refrigerant without a leak?

Refrigerant is a working chemical that runs through your car's A/C system in either a gaseous or liquid form. Causes of refrigerant leaks in your vehicle include physical damage, wear and tear over time, and escaping refrigerant even without a leak.

How long to leave AC off to reset?

Shut off your system by hitting the isolation switch, wait 30 to 60 minutes and then turn it back on. This manual reboot fully disconnects your AC unit from power, allowing all electrical components to reset.

How do I get my AC to kick on?

Follow these steps.
  1. Step 1: Check the thermostat. Make sure that your thermostat is set to "cool" and not "heat" (if it's set to heat, your AC won't turn on no matter what). ...
  2. Step 2: Check the air filter. ...
  3. Step 3: Check the circuit breakers. ...
  4. Step 4: Clear the condensate drain.

Will resetting the breaker fix AC?

In the majority of cases, your AC system will return to functioning normally after this breaker reset. It's important to know that this isn't an instant fix and may take up to an hour to get back up and running as normal again.

Why is AC not blowing cold air?

First, check your filters and coils for dirt and debris that may be impeding airflow. Once you've cleaned the filters and coils, run the air conditioner with just the fan so that the ice accumulation can melt off. If the AC still doesn't blow cold air, it could be that refrigerant levels are too low.

Why does my window air conditioner turn on and off repeatedly?

Your air conditioner turning on and off repeatedly is known as short cycling. This behavior typically occurs due to issues like an improperly placed thermostat, dirty air filters, or low refrigerant levels. Short cycling forces your system to work harder, leading to increased energy costs and potential system failure.

Can thermostat cause AC to short cycle?

Several issues can cause short cycling, such as an oversized HVAC system, a clogged air filter, or a malfunctioning thermostat. Low refrigerant levels or a blocked evaporator coil can also force the system to shut down prematurely.

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