Lennox Error Codes: (Causes, Meanings & Fixes) Complete Guide

Lennox Furnace Error Codes: Lennox has a big name among all the HVAC companies. Many users have trust in this name and are using products developed and designed by this company for many years. 

But, as it has a big name, there are many errors that users face frequently, and in this guide, we are going to touch on almost all the common errors that users face on their Lennox furnace.

Lennox Furnace Error Codes List

There are a lot of errors that a Lennox furnace has, some of them can be fixed on your own but, some not. To fix some errors, you have to call a professional. Don’t worry, before spending your money on a professional, it is good to try fixing the error on your own. 

This guide has included methods for each error that can fix if you apply them properly. 

Lennox Error Code 426

Lennox Error Code 426 is a critical error that is related to the outdoor unit. Users may face an error message associated with this error that is- “Excessive inverter alarms.” This error code usually appears when the outdoor contour is lockout after 10 faults within one hour.

To fix this error code, disconnect the outdoor unit from the power and restart it. This should fix the error, if it fails, call a Lennox tech.

Lennox Error Code 430

Lennox Error Code 430 could be a moderate or critical error and relates to the outdoor unit. This error code indicates compressor startup failure. When this condition is detected, the outdoor unit will stop functioning, and this would be a moderate condition. If the same condition occurs 10 times within an hour, the whole system will lock out, and this would be a critical condition.

To Fix this error, disconnect the outdoor unit from the power and restart it. This should fix the error, if it fails, call a Lennox professional.

Lennox Error Code 271

Lennox Error Code 271 usually indicates that the furnace is away from the power. This could be due to the outlet not passing sufficient power to the furnace, a dirty filter, broken wires in the blower motor, or sometimes, a defective thermostat.

To fix this error code, follow these simple tricks:

1. Check the outlet and make sure that the power is coming from it or not.

2. Clear the dirt filter, and if it needs, replace it.

3. The blower motor may have defected or broken wires, need to contact a Lennox tech.

4. Replace the Thermostat if it is defective.

Also Read: Lennox Mini Split error codes and their Solution

Lennox Error Code 250 or E250

Lennox Error Code 250 or E250 means the furnace’s primary limit switch is open. This error code is a moderate error. To fix this error code, Check for the proper firing rate on the furnace, confirm that there is no blockage in the furnace and the duct, and Check for proper airflow.

If nothing helps, call a Lennox assistant or professional.

Lennox Error Code E126 or 126

This error code is an internal communication issue with the control. This may arise due to some hardware issues or circuit issues. Call a professional to deal with this error.

Lennox Error Code 532

Lennox Error Code 532 usually affects the damper control module and indicates that the joining pressure switch is opened (high pressure). This usually happens when pressure is above the specified limit or the compressor is turned off. 

Set the compressor pressor within the limit to fix this error code. If you are not able to do that, call a professional.

Lennox Error Code 310

Lennox Error Code 310 generally affects Furnaces, air handler equipment, interface modules, or damper control modules. Users see this error usually when there is a discharge air temperature sensor problem. 

How to Fix Lennox Error Code 310?

To fix this error, follow these steps:

• Compare outdoor discharge sensor resistance to temperature. (In the resistance charts in system component installation instruction)

• Replace the discharge air sensor if necessary.

• Call a professional, if needed.

Lennox Error Code 273

Lennox Error Code 273 is related to the furnace and usually appears when the furnace flame goes off during a heating cycle. This is a critical error, and when this appears, the system goes into WatchGuard mode. 

To fix this error:

1. Check micro-amperes of the flame sensor using the thermostat diagnostics.

2. Clean or replace the sensor, as the second step.

3. Measure the voltage of neutral to ground to confirm good unit ground. 

4. Call a professional, if feels something wrong.

Lennox Error Code 410

Lennox Error Code 410 is a moderate error that relates to the outdoor unit. This error code usually appears when the unit’s low-pressure measures are below the required limit. Call a Lennox tech to deal with this error.

Lennox Error Code 223

Lennox Error Code 223 is non-neglecting as it is a critical error. This is related to the Furnace and usually indicates that the furnace’s low-pressure switch is open. 

Call a professional to deal with this error.

Lennox Error Code 312

Lennox Error Code 312 indicates an issue with the Furnace or air handler. Usually, this error code arises if the indoor blower fails to provide the requested CFM due to high static pressure. This code is a warning

In other words, error code 312 on Lennox usually means that your furnace is distributing less heat. A dirty filter is one of the most common causes of this error code.

How to Fix Lennox Error Code 312?

• Check the air filter and clean it, if necessary, change it.

• If after changing or clearing the air filter, the error code is still appearing, call a professional to look into this.

Lennox Error Code 201

Lennox error code 201 indicates a communication issue with your furnace and the indoor blower motor. The indoor blower distributes warm air, so if this error code is appearing, you won’t have heat.

As the possible cause, you can consider- A power outage, A brown-out, the motor not receiving power, wiring issue, condensation on uncovered system component controls, or a flipped breaker.

How to fix Lennox Error Code 201?

Follow these steps to fix this error:

• Make sure the furnace switch is set to the ON position.

• Check the air filter and the breaker box.

• If any doubt, call a professional.

Lennox Error Code 207

Lennox error code 207 denotes an issue with the hot source ignitor. This usually indicates that the hot source igniter is open. A hot source ignitor lights the gas in your furnace that creates heat. When this error appears, your furnace won’t turn on for safety reasons.

Call a professional to solve this error code.

Lennox Error Code 125

Lennox Error Code 125 indicates a hardware issue that can be with the thermostat, furnace, air handler, outdoor unit, equipment interface, or damper control module. To fix this error code, you will need to call a professional as the control board may need to be replaced.

Final Thoughts

We have included almost all the common Lennox error codes in this blog to make this a complete guide on Lennox error codes and their solutions. If your error is not mentioned in this guide, comment to us.

We hope, you have found the solution for your Lennox error code and solved that error using this guide. Don’t forget to share your opinion.

Frequently Asked Questions

Flickering Light on Lennox Heating System: What does it Mean?

If you have noticed one light going ON and OFF quickly and the other going ON and OFF slow, this usually means that your furnace may have a low flame signal. 

The pair of LED lights are off: What does it Mean?

If the pair of LED lights are off, this usually means that your HVAC system is not having electricity.

All lights are flickering slowly, what does it Mean?

If all the lights are flickering slowly, this usually means that your heater’s blower motor possibly isn’t operating.