4 Ways to Reset Your Air Conditioning System

July 2, 2024

It’s a blistering hot summer day, and your home feels like a sauna. You rush to your air conditioning unit for relief, only to find it’s not working. Before you panic and call for help, try resetting your A/C system. This often-overlooked step can be a simple solution to common issues.

Common Reasons for Needing a Reset

Tripped BreakersOften caused by power surges or electrical faults.
Power OutagesDisrupts the balance of your A/C’s electrical components.
System OverloadsRunning the A/C at maximum capacity for extended periods can cause shutdown.

Benefits of Resetting Your A/C

Restoring FunctionalityClears minor glitches and restores full operational status.
Preventing Further IssuesAddresses minor problems early to avoid serious, costly repairs.
Saving Time and MoneyQuick fix that can often be done without professional help, saving on service calls and repairs.

Method 1: Using the Reset Button

  1. Power Down the A/C
    Turn off your air conditioning system at the thermostat.
  2. Locate the Reset Button
    Usually found on the outdoor unit, often a small, red button labeled “RESET.”
  3. Hold the Button for 3-5 Seconds and Release
    This should reset the internal systems.
  4. Restore Power and Test the System
    Turn the A/C back on at the thermostat, set it to “cool,” and check for cool air.

Troubleshooting Tips if the Reset Button Doesn’t Work

  • Check the Power Supply
    Verify the circuit breaker hasn’t tripped and the outdoor unit’s power switch is on.
  • Inspect the Thermostat
    Ensure it’s set to “cool” and the temperature is appropriately set.
  • Examine the Outdoor Unit
    Clear any debris that might be blocking airflow or affecting performance.

Method 2: Resetting from the Isolator Switch

  1. Locate the Isolator Switch
    Typically near the outdoor unit, in a V-shaped socket or lever.
  2. Turn Off the Isolator Switch and Wait for 30 Minutes
    This disconnects the unit from the electrical supply.
  3. Turn the Switch Back On and Test the System
    Turn your A/C back on at the thermostat and check for cool air.

Troubleshooting Tips if the Isolator Switch Doesn’t Work

  • Check Older Models and Alternate Locations
    The switch might be in the garage, basement, or utility closet.
  • Consult the Manual
    For specific instructions related to your model.
  • Seek Professional Assistance
    If the system doesn’t reset, contact an HVAC technician.

Method 3: Resetting the Circuit Breaker

  1. Turn Off the A/C Using the Thermostat
    Set it to the “off” position.
  2. Locate the Breaker Box and Identify the A/C Breaker
    Typically found in the garage, basement, laundry room, or exterior part of your home.
  3. Turn Off the Breaker for at Least a Minute
    Switch the A/C breaker to the “off” position and wait.
  4. Turn the Breaker Back On and Wait for 30 Minutes Before Restarting the A/C
    Ensure any residual charge has dissipated.
  5. Test the System
    Set your thermostat to “cool” and check for cool air.

Troubleshooting Tips if the Breaker Reset Doesn’t Work

  • Check for Continuous Tripping
    Could indicate faulty wiring or an overloaded system.
  • Inspect the Thermostat and A/C Unit
    Ensure settings are correct and clear any debris.

Method 4: Resetting from the Thermostat

  1. Replace or Remove the Batteries if Needed
    Check and replace batteries.
  2. Locate the Reset Button on the Thermostat
    Often found on the face or under the cover.
  3. Hold the Reset Button for 5 Seconds
    This resets the thermostat’s settings.
  4. Test the System by Setting the Thermostat to a Lower Temperature
    Check if the A/C unit starts blowing cool air.

Troubleshooting Tips if the Thermostat Reset Doesn’t Work

  • Check Thermostat Settings
    Ensure it’s set to “cool” and the temperature is set lower than the room temperature.
  • Inspect the Thermostat’s Location and Wiring
    Make sure it’s not near heat sources and connections are secure.

Additional Tips and Considerations

If the A/C Still Doesn’t Start After a Reset

  1. Double-Check Power Supply
    Ensure the A/C unit is receiving power.
  2. Inspect Thermostat Settings
    Verify mode and temperature settings.
  3. Check for Obstructions
    Clear any blockages affecting the system.
  4. Look for Error Codes
    Consult your unit’s manual for error codes.

Signs That Indicate a Need for Professional Assistance

  • Repeated Tripping of the Circuit Breaker
  • Persistent Warm Air from Vents
  • Unusual Noises or Smells from the A/C Unit
  • Visible Damage or Leaks
  • High Energy Bills

Maintaining your air conditioning system is crucial for efficient and reliable operation. Regular maintenance and prompt attention to problems will keep your system running smoothly and extend its lifespan.


Resetting your A/C can clear minor faults and glitches, prevent further damage, and ensure safe and efficient operation. Whether it’s after a power outage or due to a tripped breaker, knowing how to reset your A/C can save you time, money, and discomfort.

Summary of the Methods Discussed

Using the Reset ButtonPower down the A/C, locate the reset button, hold for 3-5 seconds, and restore power.
Resetting from the Isolator SwitchTurn off the isolator switch near the outdoor unit, wait for 30 minutes, then turn it back on.
Resetting the Circuit BreakerTurn off the A/C using the thermostat, switch off the breaker for at least a minute, turn it back on, and wait 30 minutes before restarting.
Resetting from the ThermostatReplace or remove batteries if needed, locate the reset button, hold for 5 seconds, and test the system by setting the thermostat to a lower temperature.

By following these methods, you can often resolve minor issues with your air conditioning system, ensuring a comfortable and cool home.