Lennox Furnace Error Codes

Understanding and troubleshooting Lennox furnace error codes is essential for maintaining the functionality of your furnace.

Lennox furnaces utilize a sophisticated system of error codes to communicate issues and malfunctions. These error codes are displayed through LED lights on the furnace control panel. By understanding the meaning behind each error code, homeowners and technicians can quickly identify and resolve problems.

How to Read Lennox Furnace Error Codes

To read a Lennox furnace error code, locate the LED light on the furnace control panel. The light will blink in a specific pattern, indicating a particular error code. It is essential to note the number of times the light flashes and the speed of the blinking. By referring to the furnace’s error codes list, which can usually be found on the inside of the front cover, you can determine the meaning of the error code.

Common Lennox Furnace Error Codes and Troubleshooting Steps

Here are some of the most common Lennox furnace error codes and the corresponding troubleshooting steps:

E200: The furnace rollout limit switch is open

  • Potential Issue: The furnace rollout limit switch is open.
  • Troubleshooting Steps: Reset the roll-out switch, test the furnace operation, check for blocked or obstructed vent pipes, and inspect the flame stability. If the flame is unstable, it is recommended to call an HVAC technician.

E201: Lost communication with indoor blower motor

  • Potential Issue: Lost communication with the indoor blower motor.
  • Troubleshooting Steps: Check for a power outage, brown-out, loose wiring, or condensation on the system component control. If necessary, call an HVAC technician to address the issue.

E223: The furnace low-pressure switch is open

  • Potential Issue: The furnace’s low-pressure switch is open.
  • Troubleshooting Steps: This indicates a problem with the furnace’s low-pressure switch. It is crucial to call a licensed HVAC technician to diagnose and fix the issue.

E241: Flame Sensor out of Sequence

  • Potential Issue: The flame sensor is out of sequence.
  • Troubleshooting Steps: Clean the flame sensor to ensure proper functioning. If the problem persists, it is recommended to call a licensed HVAC technician for further assistance.

E292: Indoor blower motor unable to start

  • Potential Issue: The indoor blower motor is unable to start.
  • Troubleshooting Steps: This error code indicates that the furnace’s blower motor needs to be replaced. It is recommended to contact an HVAC technician to replace the faulty motor.

When to Seek Professional Help

While some Lennox furnace issues can be resolved through troubleshooting, there are certain situations where it is best to seek professional help. If you encounter any of the following problems, it is advisable to contact a licensed HVAC technician:

  1. Gas Odor: If you smell gas in your home, it is crucial to leave immediately and call 9-1-1 and an HVAC professional. A strong, persistent gas odor could indicate a serious gas leak.
  2. Unusual Noises: Loud hissing or banging noises coming from your furnace may indicate a more significant problem. It is best to call an HVAC professional to inspect and troubleshoot your furnace in this case.
  3. Ineffective Troubleshooting: If you have followed all the recommended troubleshooting steps and your furnace is still not functioning correctly, it is time to call in a professional. Only a trained technician can accurately diagnose and resolve complex furnace issues.

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Lennox Furnace Warranty Coverage

Lennox furnaces come with warranty coverage for parts and heat exchangers. The specific warranty duration depends on the furnace model:

  • Dave Lennox Signature Collection series: These furnaces offer a 10-year warranty on covered components and a 20-year warranty on the heat exchanger.
  • Elite Series and Lennox Merit series: These models come with a five-year warranty on covered components and a 20-year heat exchanger warranty.

Additionally, by registering your furnace after installation, you may be eligible for an extended limited warranty. This extended warranty can provide additional coverage for certain models in the Lennox Merit series.

Tips for Preventing Furnace Issues

While troubleshooting Lennox furnace error codes is essential, taking preventive measures can help avoid issues altogether. Here are some tips for preventing furnace problems:

  1. Regular Maintenance: Schedule annual maintenance for your Lennox furnace to ensure it operates efficiently. A professional technician can inspect and clean the furnace, identify potential issues, and perform necessary repairs or adjustments.
  2. Air Filter Replacement: Regularly replace the air filter in your Lennox furnace according to the manufacturer’s recommendations. A clean air filter improves air quality, enhances furnace efficiency, and prevents dust and debris buildup.
  3. Clear Vent Pipes: Check the intake and exhaust vent pipes for any blockages or obstructions. Clear away debris such as leaves, snow, or other foreign objects that may restrict airflow.
  4. Monitor Flame Stability: Periodically inspect the flame stability of your furnace. If the flame appears unstable or irregular, contact an HVAC technician to assess and resolve the issue.


Understanding and troubleshooting Lennox furnace error codes is crucial for maintaining the optimal performance of your heating system. By following the steps outlined in this comprehensive guide, homeowners and HVAC technicians can effectively diagnose and resolve common furnace issues. Remember to prioritize safety and seek professional help when necessary. With regular maintenance and preventive measures, your Lennox furnace will continue to provide reliable and efficient heating for years to come.

Disclaimer: This guide is for informational purposes only and should not replace professional HVAC services. If you are unsure or uncomfortable with performing any troubleshooting steps, it is recommended to contact a licensed HVAC technician.