BoilerFaultCodesThe 6 most common faults
Your boiler's pilot light is going out as soon as you let go of the control knob, meaning the burner cannot stay lit to provide heat.
Turn the control knob to the off position (following the arrow).Wait at least 3 minutes for any unburnt gas to clear.Follow the lighting instructions: press and hold the knob fully in while sparking the igniter.Continue holding the knob for 20-30 seconds after the flame appears before releasing slowly.
Your boiler has lost its connection to the power supply or the main control board has experienced a temporary communication error.
Check if other electrical appliances in your home are workingCheck your fuse box to ensure the boiler circuit hasn't trippedSwitch the boiler power off and back on again to attempt a reset
Your boiler has failed to ignite, which means it cannot provide any heating or hot water until the flame is established.
Check that your gas supply is turned on at the meterPress and hold the reset button for several secondsConfirm that other gas appliances in your home, like a hob, are working correctly
Your boiler has detected that the core part responsible for heating your water is failing to transfer heat properly, causing the system to shut down for safety.
Full guide for 26Your boiler's internal air extraction system is failing, which prevents it from safely igniting and providing heating or hot water.
Full guide for 28Your boiler is struggling to clear exhaust fumes safely, so it has turned itself off to prevent any risk.
Full guide for 29on the Alpha 240XE
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 Alpha 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