BoilerFaultCodesThe 6 most common faults
01
08 High DIY-safe
Your boiler has stopped working because the water pressure inside the system is too low to operate safely.
What to try first
Locate the filling loop (usually a flexible silver hose) underneath the boiler.Open the valves to allow mains cold water into the system until the pressure gauge reads between 1.0 and 1.5 bar.Close both valves tightly to stop the inflow of water.
02
01 High Engineer
Your boiler has detected an ignition failure, meaning it is failing to light the flame required to provide heating and hot water.
Full guide for 0103
03 High Engineer
Your boiler is trying to start, but it cannot sense a steady flame, so it has safely shut itself down to prevent gas from building up.
Full guide for 0304
07 High Engineer
Your boiler has detected that water is not flowing properly around your heating system, so it has safely shut down to prevent overheating.
Full guide for 0705
09 High Engineer
Your boiler is struggling to detect the temperature of your hot water supply, so it has safely decided to stop heating your taps.
Full guide for 0906
10 High Engineer
Your boiler is struggling to accurately measure the temperature of your hot water, which means it has stopped heating it to prevent the system from overheating.
Full guide for 10on the Chaffoteaux Talia Green 25
Pressure relief valvePressure gaugeExpansion vesselIgnition electrodeGas valvePrinted Circuit Board (PCB)
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