BoilerFaultCodesThe 6 most common faults
01
WATER TEMPERATURE LOW High Engineer
Your boiler is struggling to heat the water to the right temperature because the water is flowing through the system too quickly or the gas supply isn't strong enough.
Full guide for WATER TEMPERATURE LOW02
BURNER STAYS ON High Engineer
Your boiler is failing to switch off even when it should, which means it will continue to run constantly and may overheat.
Full guide for BURNER STAYS ON03
INSUFFICIENT WATER FLOW High Engineer
Your boiler is struggling to detect enough water flowing through it to safely start your hot water.
Full guide for INSUFFICIENT WATER FLOW04
POOR PILOT FLAME Emergency Engineer
Your boiler's small starter flame is too weak to safely ignite the main burner, causing the system to shut down to prevent gas build-up.
Full guide for POOR PILOT FLAME05
EXPLOSIVE IGNITION Emergency Engineer
Your boiler is struggling to light smoothly and is building up gas before catching, causing a small bang or flash when it starts.
Full guide for EXPLOSIVE IGNITION06
UNSTABLE FLAMES Emergency Engineer
Your boiler is struggling to keep the fire lit safely, which could prevent your heating or hot water from working consistently.
Full guide for UNSTABLE FLAMESon the Chaffoteaux Corvec 28 OF BF
Water governorGas valveDiaphragmWater section assemblyDHW flow switchVenturi
Based on parts cited in our fault code database. Your engineer will confirm what's actually needed after diagnosis.
Call a Gas Safe engineer if…
- You can smell gas or see signs of a leak
- The Chaffoteaux shows an Emergency or High severity code
- The boiler keeps locking out after repeated resets
- You've tried the DIY checks and the fault hasn't cleared
- There's visible water leaking from the boiler
- The flame is yellow or orange instead of blue