Run capacitor
Common no-start and weak-compressor failure point. Match the microfarad and voltage rating.
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.
Lennox Elite Series Flash Code / Alert Code Reference
| Flash Code | Alert Code | Fault |
|---|---|---|
| 2 flashes | 111 | Pressure switch stuck open |
| 3 flashes | 112 | Pressure switch stuck closed |
| 4 flashes | 223 | Open high-limit device |
| 5 flashes | 224 | Rollout switch open |
| 6 flashes | 225 | Flame not established at end of trial |
| 7 flashes | 411 | Ignition lockout — 3 retries failed |
| 8 flashes | 412 | Flame sensed without gas valve call |
| 9 flashes | 414 | Low gas pressure |
| 10 flashes | 431 | Communication fault (iComfort) |
| 11 flashes | 432 | Blower fault |
| 12 flashes | 434 | Inducer motor fault |
| Rapid | 540 | Control board fault |
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
- 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.
- 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).
- 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).
- 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.
- 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
| Part | Notes |
|---|---|
| SureLight igniter | Silicon nitride; part number varies by model |
| Flame sensor | Clean with fine steel wool; measure µA output |
| Pressure switch | Single or dual switch depending on model |
| ECM blower motor module | Replace module only if motor spins freely |
| High-limit switch | Check reset button — some are auto-reset, some manual |
| Rollout switch | Manual-reset; do not bypass |
Technician Tips
Lennox furnace error codes are displayed as a series of LED flashes on the SureLight or integrated control board. A slow flash usually indicates normal operation, while rapid flashing points to a specific fault code. Code 1 = no previous code (normal standby). Code 2 = pressure switch failed open — check the vent, condensate drain, and inducer motor. Code 3 = pressure switch failed closed — replace the switch. Code 4 = high temperature limit — check airflow. Lennox systems with the SureLight igniter are particularly sensitive to gas pressure — verify 3.5” WC on natural gas before troubleshooting further. A 5-minute gas pressure check can save an hour of unnecessary component swapping.
Need Replacement Parts?
Before ordering, match the furnace part to the model number, electrical rating, and failure symptom. Check current prices on Amazon - prices and availability change frequently.
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