BoilerFaultCodesThe 6 most common faults
Your boiler has stopped working because the water pressure inside the system has dropped too low or there is trapped air causing a blockage.
Locate the pressure gauge on your boiler; it should be between 1 and 1.5 bar.If the pressure is below 1 bar, use the filling loop (a silver flexi-hose) to carefully top up the system with water until it reaches the green zone.Bleed your radiators to remove any trapped air, then re-check the pressure gauge and top up if necessary.
Your boiler is not receiving a signal to turn on, which is likely due to the timer settings or the thermostat connections not communicating correctly.
Check your external wall thermostat or programmer is set to 'On' and the temperature is turned up higher than the current room temperatureEnsure your boiler's internal clock is set to the correct time and is currently within an 'On' periodReplace the batteries in your wireless room thermostat if applicable
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 is failing to detect that you have turned on a hot water tap, so it is refusing to heat the water for you.
Full guide for 13on 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