Lennox Elite Series Furnace Error Codes — Fault Code Diagnostic Guide

Lennox Elite Series Furnace Error Codes — What They Mean

The Lennox Elite Series includes several residential gas furnace models: the EL195E, EL180E, EL296V, and G61MPV among others. These furnaces use Lennox’s SureLight control board system, which reports faults through a status LED (flash codes) on non-communicating models or through three-digit alert codes on iComfort-enabled systems. Elite Series furnaces range from 80% to 96% AFUE and include single-stage, two-stage, and variable-speed variants.

Jump to Fix

Lennox Elite Series Flash Code / Alert Code Reference

Common Causes by Code

• 2 flashes / Alert 111 — Pressure switch open — On 90%+ Elite models, check the condensate drain and the secondary heat exchanger for water blockage. On 80% models, check flue gas venting for obstruction. The inducer must run and create negative pressure before the pressure switch closes.
• 4 flashes / Alert 223 — High limit — Restricted airflow is the primary cause. Lennox Elite Series blowers use either PSC or ECM motors — on ECM models, a failed motor module can reduce airflow even with no obvious symptom.
• 5 flashes / Alert 224 — Rollout switch — This is a safety shutdown. The rollout switch trips when flames leave the burner box — caused by a blocked heat exchanger, cracked cell, or excessive gas pressure. Do not bypass. Find the root cause.
• 6/7 flashes / Alert 225/411 — Ignition failure — SureLight HSI igniter, gas valve, and flame sensor are all in the diagnostic path. Check gas supply, manifold pressure (3.5” WC natural gas), and igniter resistance (40–70 Ω cold for silicon nitride).
• 11 flashes / Alert 432 — Blower fault — ECM blower motor fault or failed hall-effect sensor connection. Also check the iComfort board’s blower configuration parameters — a misconfigured airflow setting can cause the motor to run at wrong speed and trigger a fault.

Step-by-Step Fix {#fix}

1. Check the thermostat first — On iComfort systems, the thermostat displays the alert code number (e.g., 223) with a description. Navigate to System > Alerts. Write down the active and historical codes.
2. For pressure switch (2 flashes / Alert 111) — Disconnect the pressure switch tubing and blow through it — it should be clear. Connect a manometer to the inducer outlet port and confirm the inducer creates at least -0.5” WC (the switch setpoint is labeled on the switch body).
3. For limit (4 flashes / Alert 223) — Replace the air filter. Run the furnace with the blower door removed and measure air temperature rise across the heat exchanger — should be between 35°F and 65°F (check the nameplate for the model-specific range).
4. For rollout switch (5 flashes / Alert 224) — Do not reset until the cause is identified. Inspect the heat exchanger for cracks using a flashlight through the burner ports. Also measure gas manifold pressure — should be 3.5” WC natural gas, not higher.
5. For ignition failure (7 flashes / Alert 411) — Watch the ignition sequence through the sight glass. Time the igniter warm-up (17–40 seconds depending on model). If the igniter glows and gas doesn’t light, check gas valve operation with a voltmeter at the valve terminals (24VAC on call for heat).

Parts Often Needed

When to Call a Pro

Lennox Elite Series furnaces with iComfort communicating systems require Lennox service tools for full diagnostics. Alert Code 540 (control board fault) and any code that returns after a verified repair should be evaluated by a Lennox Premier Dealer. Heat exchanger inspection for rollout switch trips requires camera inspection equipment and combustion analysis.

See Also

• Lennox Error Code 540 — Causes & Fix
• Lennox Harmony III Zoning System Error Codes — Complete Guide
• Lennox Error Code 231 — Causes & Fix
• Lennox Error Code 111 — Causes & Fix

Related Articles

• Lennox Error Code 292 — Ignition Failure Fix
• Lennox EL296V Error Codes — Variable-Speed Furnace Diagnostic Guide
• Lennox 103 Error Code — Causes & Fix
• Lennox Error Code 111 — Causes & Fix
• Lennox Error Code 114 — Causes & Fix