BoilerFaultCodesThe 6 most common faults
01
A. (2) High DIY-safe
Your boiler is struggling to ignite the small starting flame because the ignition control hasn't been held down long enough to establish a gas flow.
What to try first
Ensure the gas supply to the boiler is turned on.Turn the control knob to the ignition position and press it down fully.Hold the knob down firmly for at least 15 to 20 seconds while clicking the igniter to allow the pilot light to catch.
02
A. (1) High Engineer
Your boiler is failing to ignite because it is not receiving the gas it needs to start the flame.
Full guide for A. (1)03
A. (3) High Engineer
Your boiler is unable to start up because the small flame that acts as a trigger is being blocked from lighting, which means the boiler cannot heat your home or water.
Full guide for A. (3)04
A. (4) High Engineer
Your boiler's pilot light is failing to spark, which means it cannot ignite to start the heating and hot water process.
Full guide for A. (4)05
A. (5) High Engineer
Your boiler is failing to start because it cannot create the spark or flame needed to ignite its main burner.
Full guide for A. (5)06
A. (6) High Engineer
Your boiler has stopped working because the pilot light won't ignite and a safety device has prevented it from starting to prevent overheating.
Full guide for A. (6)on the Potterton Kingfisher 2
Pilot burner assemblyThermocouplePiezo igniterGas valvePilot assemblyPilot injector
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 Potterton 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