Common Boiler Error Codes — What They Mean and How to Fix Them
Published: July 23, 2026 — BC Wide Home Services Ltd, doing business as BC Wide Heating & Air Conditioning — Greater Vancouver, BC
Navien Common Error Codes
E001: Ignition failure — check gas supply, reset boiler. If persistent, the ignitor or flame rod may need service. E003: Flame loss — check condensate drain, venting. E110: Overheating — scale buildup needs descaling. E301-303: Flow sensor issues — clean inlet filter. E416: Voltage issue — check electrical connection.
Viessmann Common Error Codes
A0, A1: Burner fault — ignition or flame sense issue. B0, B1: Sensor fault — temperature sensor may need replacement. C0, C1: Pump fault — circulation pump may be seized. F0: Flue gas temperature too high — blocked heat exchanger. F1: Safety chain fault — multiple safety devices triggered.
Baxi Common Error Codes
E10: NTC fault — temperature sensor issue. E20: NTC short circuit — temperature sensor shorted. E50: Air pressure switch — check venting. E96: Fan fault — fan speed incorrect. E110: Overheat — heat exchanger or flow issue. H02: CH temperature too high — check pump operation.