Lennox Error Code and Repair Guides - 44 Guides
Lennox HVAC troubleshooting hub with 44 guides for fault codes, alarms, symptoms, parts checks, and repair decisions.
Use this page when your Lennox furnace, air conditioner, heat pump, or mini split is flashing a fault. Start with the exact code, then open the fix guide to diagnose airflow, ignition, sensor, pressure switch, board, or communication problems before you order parts or book a service call.
Tip: search the exact brand, model, and code together, for example "Lennox error code 13" or "Lennox pressure switch fault".
Start With These Lennox Guides
Lennox Error Code 292 — Ignition Failure Fix Lennox 292 ignition-lockout guide for hot-surface igniters, flame sensors, gas valves, supply pressure, control boards, and resets. Lennox Furnace Blink Codes — Complete Red Light Guide Use this Lennox Furnace Blink Codes - Complete Red Light Guide reference to match the code with likely causes, service checks, and repair decisions. Lennox EL296V Furnace Error Codes Lennox EL296V furnace guide for ignition, limit, pressure-switch, flame-sense, gas-valve, inducer, and ECM blower faults. Lennox Error Code 412 — Inducer Motor Fault (Detailed Guide) Lennox Error Code 412 - Inducer Motor Fault (Detailed Guide): likely causes, checks, and repair decisions before replacing parts. Lennox iComfort Error Code 225 — Communication Fault Fix Guide Lennox iComfort Error Code 225 - Communication Fault Fix Guide: likely causes, checks, and repair decisions before replacing parts. Lennox SL280UHV Error Codes Lennox SL280UHV guide for SureLight codes, limit faults, igniter failures, flame-sense problems, pressure switches, filters, and blower issues.
Lennox FAQ
Where should I start with Lennox error codes?
Start with the exact Lennox model and displayed code or alarm, then open the closest guide on this page. Match the symptom, recent service history, and any secondary codes before resetting the equipment or ordering parts.
Do Lennox fault codes always mean a bad control board?
No. Many Lennox codes point to airflow, water flow, sensors, wiring, power quality, filters, switches, or operating conditions. Check the simple causes in the guide before replacing an expensive board.
When should I stop troubleshooting a Lennox fault myself?
Lennox HVAC equipment can hide unsafe ignition, refrigerant, high-voltage, or combustion problems behind a simple blinking code. Stop and use the repair checklist or compare service options when the guide points to gas, refrigerant, line voltage, sealed-system work, food-safety temperatures, or repeated faults after a reset.
| Error Code | What It Means | Guide |
|---|---|---|
| Lennox Error Code 292 | Ignition Failure Fix | Fix → |
| Lennox Furnace Blink Codes | Complete Red Light Guide | Fix → |
| Lennox EL296V Furnace Error Codes | Lennox EL296V furnace guide for ignition, limit, pressure-switch, flame-sense, gas-valve, inducer, and ECM blower faults. | Fix → |
| Lennox Error Code 412 | Inducer Motor Fault (Detailed Guide) | Fix → |
| Lennox iComfort Error Code 225 | Communication Fault Fix Guide | Fix → |
| Lennox SL280UHV Error Codes | Lennox SL280UHV guide for SureLight codes, limit faults, igniter failures, flame-sense problems, pressure switches, filters, and blower issues. | Fix → |
| Lennox Rooftop Unit Error Codes: Technician Guide | Lennox rooftop unit code guide for LGH, LCH, LCA, and Strategos units: flash codes, ignition lockouts, pressure trips, blower faults, and resets. | Fix → |
| Lennox Harmony III Zoning System Error Codes | Complete Guide | Fix → |
| Lennox Healthy Climate Error Codes | Complete Guide | Fix → |
| Lennox ResolvePlus Rooftop Unit Error Codes: Complete Guide | Lennox ResolvePlus RTU error codes and fault diagnostics. Covers flash codes, communicating system faults, and technician-level troubleshooting. | Fix → |
| Lennox 103 Error Code | Causes & Fix | Fix → |
| Lennox 204 Error Code | Causes & Fix | Fix → |
| Lennox 540 Communication Fault | Lennox 540 means an iComfort device lost communication. Check thermostat, indoor unit, outdoor board, RS-bus wiring, and zoning modules. | Fix → |
| Lennox Elite Furnace Error Codes | Lennox Elite furnace guide for SureLight flash codes, iComfort alerts, pressure switches, rollout trips, ignition faults, and blower errors. | Fix → |
| Lennox Error Code 111 | Causes & Fix | Fix → |
| Lennox Error Code 114 | Causes & Fix | Fix → |
| Lennox Error Code 125 | Causes & Fix | Fix → |
| Lennox Error Code 223 | Causes & Fix | Fix → |
| Lennox Error Code 225 | Causes & Fix | Fix → |
| Lennox Error Code 231 | Causes & Fix | Fix → |
| Lennox Error Code 327 | Causes & Fix | Fix → |
| Lennox Error Code 332 | Causes & Fix | Fix → |
| Lennox Error Code 411 Ignition Proving Fault | Lennox 411 guide for ignition proving faults, flame-sensor signal, igniter checks, gas-pressure symptoms, lockout resets, and service limits. | Fix → |
| Lennox Error Code 412 Limit Switch Fault | Lennox 412 guide for high-limit trips, overheating causes, airflow checks, filters, blower issues, iComfort/SLP faults, and reset limits. | Fix → |
| Lennox Error Code 414 | Gas Valve Circuit Fault Fix | Fix → |
| Lennox Error Code 414 Rollout | Rollout Switch Fault | Fix → |
| Lennox Error Code 432 | Causes & Fix | Fix → |
| Lennox Error Code 434 | Outdoor Unit Communication Fault | Fix → |
| Lennox Error Code 441 | Limit Device Fault | Fix → |
| Lennox Error Code 540 | Causes & Fix | Fix → |
| Lennox Furnace Error Codes | Complete Reference Guide | Fix → |
| Lennox G60UHV Furnace Error Codes | Lennox G60UHV furnace flash-code guide for inducer speed, pressure switches, high-limit trips, SureLight ignition, blower faults, and boards. | Fix → |
| Lennox iComfort Code 31 Pressure Switch Fault | Lennox iComfort code 31 guide for pressure switch faults, inducer draft, blocked flues, hoses, condensate drains, resets, and part checks. | Fix → |
| Lennox iComfort EFO and Common Faults | Lennox iComfort EFO means excessive flame loss. Check flame sensing, gas pressure, ignition, condensate drainage, venting, and communicating controls. | Fix → |
| Lennox iHarmony Zoning Error Codes | Lennox iHarmony guide for zone-lost, damper, sensor, bypass, communication, and discharge-air limit faults in zoning systems. | Fix → |
| Lennox Mini Split Error Code E1 | Causes & Fix | Fix → |
| Lennox SLP98V Error Codes | Variable-Speed Furnace Fault Guide | Fix → |
| Lennox XC16 Air Conditioner Error Codes | Lennox XC16 guide for iComfort alerts, high/low pressure faults, fan errors, compressor protection, sensor faults, and board checks. | Fix → |
| Lennox XC21 Error Codes | Diagnostic Guide and Fixes | Fix → |
| Lennox XP20 Heat Pump Fault Codes | Lennox XP20 iComfort fault codes for communication, inverter, sensor, pressure, defrost, and control-board problems on variable-capacity heat pumps. | Fix → |
| Lennox XP21 Heat Pump Error Codes | iComfort Fault Code Guide | Fix → |
| Best Furnace Igniter Replacement: Universal and Brand-Specific Picks | Choose a furnace igniter replacement by matching style, voltage, bracket, and brand fit before ordering a universal or OEM part. | Fix → |
| Furnace Blinking 3 Times | Cross-Brand Comparison Guide | Fix → |
| How to Reset a Furnace After Lockout | Per-Brand Reset Procedures | Fix → |