Boiler Frequent Issues — Complete List of Common Boiler Problems
Published: July 23, 2026 — CANRO Heating & Cooling — Greater Vancouver, BC
1. Pressure Loss (Most Common)
Symptom: pressure gauge drops below 1 bar, boiler displays low pressure error. Cause: slow system leak, failed expansion tank, or automatic air vent leaking. Fix: repressurize using filling loop. If frequent, professional diagnosis needed. Cost: $0 for repressurizing (DIY), $250-600 for expansion tank replacement.
2. Lockout / Error Codes
Symptom: boiler shuts off and displays an error code, will not restart. Cause: varies by code — ignition failure, overheating, sensor fault, or flue blockage. Fix: read the code, try a reset. If persistent, professional diagnosis needed. Cost: $150-300 for reset/service call, $200-800 for part replacement.
3. No Hot Water (Combi)
Symptom: central heating works but no hot water from taps. Cause: diverter valve failure, blocked plate heat exchanger, or temperature sensor fault. Fix: professional diagnosis. Cost: $300-600 for diverter valve, $200-400 for descaling, $200-400 for sensor replacement.