Run capacitor
Common no-start and weak-compressor failure point. Match the microfarad and voltage rating.
Lennox Healthy Climate Error Codes — Quick Reference
Lennox Healthy Climate is a family of air quality products including media air cleaners (HCF16), electronic air cleaners (HCX16, HCX20), HEPA filtration systems (HEPA-20), energy recovery ventilators (ERV-150, HRV-90), and UV germicidal lights (HCXUV). Error codes appear on the Lennox iComfort thermostat when these accessories are part of a communicating system, or on the unit’s own indicator LEDs.
| Code | Product | Meaning | Quick Fix |
|---|---|---|---|
| 2801 | ERV/HRV | Defrost fault | Check defrost cycle settings; inspect core |
| 2802 | ERV/HRV | Bypass damper fault | Check bypass damper actuator |
| 2803 | ERV/HRV | Supply fan fault | Check supply fan motor |
| 2804 | ERV/HRV | Exhaust fan fault | Check exhaust fan motor |
| 2805 | ERV/HRV | Communication fault | Check iComfort bus wiring |
| 2810 | ERV/HRV | Core temperature sensor fault | Inspect core temp sensor |
| E1 | Electronic air cleaner | Power supply fault | Check 24VAC supply |
| E2 | Electronic air cleaner | Cell fault | Clean or replace collector cell |
| E3 | Electronic air cleaner | Ionizing wire fault | Clean ionizing wires |
| FILTER | Media cleaner | Filter change reminder | Replace filter media |
| UV FAULT | UV system | UV lamp fault | Replace UV lamp |
Most Common Faults
2801 — ERV/HRV Defrost Fault
Energy recovery ventilators must defrost the heat exchange core in cold climates when frost builds up on the core. A 2801 fault means the defrost cycle is not completing properly. Check the defrost cycle configuration in the iComfort settings — the defrost schedule should match your climate zone. Also inspect the ERV core for ice buildup and verify the bypass damper operates freely.
E2 — Electronic Air Cleaner Cell Fault
The HCX-series electronic air cleaners use a washable collector cell to capture particles on electrically charged plates. An E2 fault means the cell is dirty enough to cause arcing or the cell has failed. Remove the collector cell and wash it with warm water and a few drops of dish soap. Rinse thoroughly and allow to dry completely before reinstalling — a wet cell will fault immediately. If the E2 fault continues with a clean, dry cell, the cell itself needs replacement.
E3 — Ionizing Wire Fault
The ionizing section of the electronic air cleaner uses thin wire stretched across a frame to impart a charge on airborne particles. If a wire breaks or becomes excessively coated with particles, E3 appears. Inspect the ionizing section with the unit powered off — look for broken, sagging, or snapped ionizing wires. Replacement ionizing wire sections are available from Lennox dealers.
UV FAULT — Germicidal Light Fault
The Healthy Climate UV light system (HCXUV) includes a lamp life monitor. When the UV lamp reaches end of life (typically 9,000–17,000 hours), the system generates a fault and disables the lamp to prevent UV output degradation. Replace the UV lamp — Lennox sells model-specific replacement lamps. After replacement, reset the lamp timer via the iComfort thermostat or the local control button.
ERV Fan Faults (2803/2804)
ERV units have separate supply and exhaust fans. A fan fault means the motor is not reaching its target RPM or has stopped. Check for:
- Blocked intake/exhaust ports (insects, debris, bird nests)
- Frozen condensate in the unit during winter
- Fan wheel obstruction
Healthy Climate Maintenance Schedule
| Component | Maintenance | Interval |
|---|---|---|
| ERV/HRV core | Clean with mild detergent | Annually |
| ERV filter | Replace | Every 3 months |
| Electronic air cleaner cell | Wash | Every 3–6 months |
| UV lamp | Replace | Annually or per runtime meter |
| Media filter (HCF16) | Replace | Annually (MERV 16) |
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 HVAC 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
ERV core replacement, defrost system reconfiguration, and persistent communication faults require a Lennox-certified technician. Never operate an ERV/HRV with a suspected frozen core — ice damage to the core is expensive to repair.