Lennox Furnace Error Codes: Complete SL280V and EL296V Fault Reference

Quick Answer

Lennox furnace error codes appear on the digital display panel on the control board. Press the diagnostic button on the control board to scroll through fault history if no code is currently displayed. Key codes include E223 (pressure switch circuit fault in the induced draft circuit, most common), E228 (inducer motor fault or stall), and 270 (ignition failure lockout after multiple attempts). E223 is by far the most common Lennox furnace code and is usually caused by a clogged condensate trap rather than a failed pressure switch. E228 and 270 typically require part replacement.

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pressure switch fault, condensate drain clog

E223

inducer motor failure or stall

E228

ignition lockout after multiple attempts

270

About These Lennox Furnace Error Codes

Lennox furnaces display alphanumeric fault codes on the digital board panel. Press the diagnostic button to scroll fault history. E223 is the most common code.

Most Common Error Codes

Clogged condensate trap or drain causing E22340%

Inducer motor failure causing E22824%

Ignition component failure causing error code 27014%

Aging components on SL280V and EL296V series12%

Flue vent blockage contributing to multiple faults10%

Symptoms You May Notice

Furnace not heating or shutting down before completing a cycle
Digital display showing an alphanumeric code
No ignition despite thermostat heat call
Blower running without heat production
Water pooling at furnace base (condensate backup)

Tools Required for Diagnosis

FlashlightLennox installation manual for your model number

How to Identify Your Error Code

Locate the control board digital display panel

Locate the control board digital display panel. On most Lennox SL280V and EL296V models it is visible through the lower cabinet observation window or by opening the lower access door. Note the exact code shown. If no code is currently displayed, press the diagnostic button (labeled DIAG or shown in the installation manual) to scroll through stored fault history.

Before deeper diagnosis

Cross-reference your code

Frequently Asked Questions

How do I access the fault code history on a Lennox furnace?

On Lennox SL280V, EL296V, and SL297NV models, the control board has a DIAG or diagnostic button. Press and release it to scroll through the last several stored fault codes on the digital display. This is useful when the furnace is currently running normally but was faulting earlier. The fault history helps identify intermittent problems that do not produce a continuously displayed code.

Where is the control board on a Lennox SL280V furnace?

On the Lennox SL280V, the control board is located in the lower cabinet section accessible by removing the lower access door. The digital display is visible through an observation window on some models, or directly when the panel is removed. The board is mounted in the lower compartment and has the diagnostic button, display, and LED indicator clearly labeled.

What is the most common error code on Lennox SL280V and EL296V furnaces?

E223 is the most frequently reported fault code on Lennox SL280V and EL296V high-efficiency models. Both are condensing furnaces that produce significant condensate, and the condensate trap is prone to clogging with algae and mineral deposits, especially at the start of the heating season after summer idle. In most E223 cases, clearing the condensate trap with a wet/dry vacuum resolves the fault without any part replacement.

Do Lennox furnaces reset automatically after an error?

Some Lennox fault codes clear automatically after the fault condition resolves and the furnace restarts. Others, such as ignition lockouts (270), require a manual reset via the thermostat or circuit breaker. Safety limit trips on some models require a physical button press on the limit switch itself. If the furnace is completely non-responsive, perform the thermostat soft reset first before assuming a component failure.

How do I find the model number on my Lennox furnace?

The model and serial number label on a Lennox furnace is located on the inside face of the lower cabinet door or on the right-hand wall inside the lower cabinet. It is a white label with the full model number, serial number, BTU rating, and electrical specifications. You will need this number to look up the correct fault code table, installation manual, and replacement parts for your specific unit.

Related Lennox Furnace Error Codes

Code: E223Lennox Furnace E223 Error Code: Pressure Switch Circuit Fault Code: E228Lennox Furnace E228 Error Code: Inducer Motor Fault Code: 270Lennox Furnace Error Code 270: Ignition Failure Lockout

Models Known to Experience HUB Errors

This repair applies to most Lennox furnaces with this error code. Common model numbers include:

SL280V, EL296V, XC21, SL297NV, EL180UH

Last verified for technical accuracy on March 14, 2026