Lennox furnace error code list

The Lennox furnace error codes can be read to determine what is happening with the machine.

Here is a list of Lennox furnace error codes that may help you diagnose the problem:

-3000 – This code indicates that the low voltage transformer has not enough power to run.

-2001 – The temperature sensor near the burner will not turn the gas valve off because it is too hot.

-4000 – The gas valve will not open because it detected a pressure difference from one side of the valve or because it detected incorrect downstream pressure about upstream pressure.

-5001 – A circuit breaker has tripped and needs to be reset.

OBD codes, or On-Board Diagnostics codes, are error codes that appear after the engine is started. OBD2 refers to the second generation of automotive onboard diagnostics and can be accessed by a connector inside the vehicle.