Resetting a Lennox air conditioner may be necessary at times, and it’s important to know the proper steps to ensure a successful reset. In this guide, we will provide a detailed explanation of the reset process, along with tips on finding the circuit breaker and the reset button for your Lennox AC unit.
To initiate the reset procedure for your Lennox air conditioner, follow these steps:
- Start by turning your thermostat to the “off” position.
- Locate the circuit breaker switch that controls your AC unit and turn it off.
- Wait for approximately 30 minutes to allow the system to fully reset.
- Turn the circuit breaker switch back on.
- Finally, set your thermostat back to the “on” position.
Now, let’s address the common question of where or how to find the circuit breaker and reset button for your Lennox air conditioner.
Locating The Circuit Breaker And Reset Button

- Find the Breaker Box
Look for a metal box, which can vary in size and shape. It is typically found in the basement, utility room, garage, or on the exterior of the house. In apartments, it might be situated in a utility closet or hallway, easily accessible to residents. - Open the Box
The breaker box will have a door on the front. Open it to reveal the circuit breakers. - Identify the AC Breaker
Inside the breaker box, you will find a series of switches. These switches should be labeled, so look for one specifically labeled “AC” or “Air Conditioner.” If the switches are not labeled, you may need to identify the correct one by trial and error, turning them off and on to determine which one controls your AC unit. - Flip the Breaker
Once you have identified the correct breaker, flip it to the “off” position. It is advisable to wait for a short period, usually around 30 seconds to a few minutes, before flipping it back to the “on” position.
Regarding the presence of a physical reset button on Lennox air conditioners, not all units have one. However, if your Lennox AC does have a reset button, it is typically located on the outdoor unit and clearly marked as the “Reset” button. If you are having difficulty locating it, consult your user manual for specific information on its whereabouts.
Now let’s discuss the reasons why you might need to reset your Lennox air conditioner and provide additional information on troubleshooting common issues.
Why Reset Your Lennox AC Unit?

There are various situations in which you may need to reset your Lennox air conditioner. Here are a few common scenarios:
- Insufficient Cooling or Unusual Noise
If your Lennox AC is not cooling your home effectively or producing loud noises, a reset may resolve the issue. Resetting the system can help restore normal functioning. - Tripped Breaker
Sometimes, the breaker associated with your AC unit might trip, causing it to stop working. Resetting the breaker can often solve this problem. - Water Leakage or Equipment Malfunction
If you notice water leakage from your Lennox AC or suspect a malfunction, a reset can be a troubleshooting step to rectify the issue. - Reactivating the AC
If you haven’t used your air conditioner for an extended period and wish to activate it again, a reset may be required to ensure proper operation. - Powering On After Turning Off
If you have manually turned off your AC at the thermostat and want to turn it back on, a reset might be necessary. - Failure to Turn On
In some cases, your Lennox AC may fail to turn on altogether. A reset can help resolve this problem and restore functionality.
If you encounter error codes or your AC unit is not operating correctly, resetting the Lennox air conditioner is often the first step in troubleshooting and resolving the issue.
While the reset button is not a standard feature on Lennox air conditioners, there is a pressure switch that can be reset to restart the system. To do this, follow these steps:
- Turn off the power to the unit by switching off the breaker associated with the air conditioner.
- Remove the back panel of the unit to access the internal components.
- Locate the liquid line, which is a copper line at the bottom of the unit.
- On the liquid line, you will find a red rubber push switch, which is the pressure switch. Press this switch to reset the pressure switch and restart the system.
If the problem persists and you notice a yellow light flashing multiple times, it indicates that there may be another underlying issue that requires professional attention.
Troubleshooting Common Lennox AC Problems

- Clogged Air Filter
Regularly clean or replace the air filter to ensure proper airflow and prevent issues with your AC unit. Cleaning or replacing the filter should be done at least once every 30 days. - Defective Thermostat
If your home isn’t cooling down or you encounter strange error codes, the thermostat may be the culprit. Check if the thermostat is damaged or requires calibration. - Reset Circuit Breaker
If the circuit breaker associated with your Lennox AC keeps tripping, it could be due to motor-related issues. Resetting the breaker can often resolve this problem, allowing the air conditioner to function properly. - Dirty Condenser Coils
Over time, condenser coils can accumulate dust and dirt, affecting the performance of your Lennox AC. Regularly clean the coils using a vacuum cleaner or a coil cleaning brush. - Failing Control Board
The internal control board in your Lennox AC is responsible for various functions, including powering the compressor and fan. If the control board fails, it may need to be replaced. - Defective Temperature Control Board
The temperature control board plays a crucial role in regulating the unit’s temperature. If it malfunctions, other parts might be incorrectly diagnosed as the problem, so check other components before replacing the temperature control board. - Faulty Temperature Control Thermostat
If the internal control board is functioning correctly, but the cooling is inadequate, a faulty temperature control thermostat could be the issue. Consider replacing the thermostat if necessary. - Bad Thermistor
A failed thermistor can hinder the cooling capabilities of your air conditioner. If this component is faulty, it should be replaced. - Input Power Failure
An input power failure indicates that the unit is not receiving electricity properly. Contact your utility company or an HVAC professional to address this issue. - Blown Blower Motor
A blown blower motor should be replaced promptly to prevent further damage to the compressor and fan. Power surges or prolonged usage can cause this problem. - Bad Condenser Fan Motor
If the condenser fan motor is faulty, it should be replaced to ensure proper functioning. A defective fan motor can lead to other issues within the unit. - Bad Run Capacitor
The run capacitor is responsible for controlling various functions of the AC unit. If it fails, it should be replaced to restore proper operation. - Faulty Fan Blade
A loose or damaged fan blade can cause rattling noises during operation. It is important to replace a faulty fan blade promptly to prevent further complications.
Lennox HVAC Reliability
Lennox air conditioners are generally reliable when properly maintained. Regular maintenance and timely repairs are crucial to ensuring optimal performance. Given the various potential causes of AC issues, it is essential to have your unit checked regularly by HVAC
professionals to detect and address any problems promptly.
Average Life Of A Lennox Air Conditioner
Lennox AC units are known for their durability and can last an average of 15 to 20 years under normal operating conditions. However, some homeowners may choose to replace their units earlier to upgrade to more efficient models.
Conclusion
While Lennox air conditioners are renowned for their reliability, occasional issues may arise. Fortunately, many common problems can be resolved by resetting the unit or addressing specific components. If problems persist, it is advisable to seek assistance from a qualified HVAC specialist.

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