What is Lennox Error Code 124, and How To Fix It?

Lennox error code 124 is a critical error that affects the thermostat, air handler, furnace, outdoor unit, equipment handler, or damper control module. This error code usually appears when the thermostat loses connectivity with the system component for more than three minutes.

Note: Usually, this error code can be caused due to several reasons, and if you know how to deal with a multimeter, fixing this error code can be easy for you.

Check if the error is real, or temporary

First of all, you should check if the error is real or temporary, before starting its troubleshooting.

• Just unplug the unit from the main source.

• Wait for a few minutes (2 to 3).

• Replug all the power cables and start the unit again.

If the problem was a temporary glitch then, it will resolve, and if still appearing, head on to its troubleshooting.

How to Fix Lennox Error Code 124?

A Lennox unit is a combination of many machines like a thermostat, outdoor unit, indoor unit, and many more. These all components are connected by a mean. When the connectivity from any component hinders, an error code may appear. Nothing to worry about, we will help you to troubleshoot this error code. 

Reset the Furnace

If the issue is with the thermostat connectivity then, to check, the best way is to rest it. We have found a good step-by-step guide on it online. To reset your Lennox Furnace, you can take help of it. If the problem resolves after doing this, means your unit is good and you can use it. If the problem is going streamlined then, move on to the next method.

Check Wiring Connections

Due to a power outage or fluctuation, wires maybe get burnt. Check carefully if any wire connection is burnt out. In this case, cut the wire from the burnt area, and use a multimeter to check if the rest of the wire is still good to flow current through it. Rejoin both ends of the wire and tape it properly, and check if the unit starts working properly or not. Once the communication starts working properly error code 124 from your Lennox unit will automatically clear out.

Circuit Board

The outdoor unit’s circuit board may get burnt due to some cause. Unscrew the outer wall, and carefully remove the circuit board. With the help of a multimeter, check if the circuit board is functional or got burnt out. If it is burnt out then, changing this component will fix the problem.

Call A Verified professional

If you don’t know how to deal with a multimeter then, calling a verified professional should be your choice and they will resolve the issue for you. Call on Lennox Assistance and they will guide you.

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