BoilerFaultCodesThe 3 most common faults
Your boiler has detected an internal fault or is not receiving a signal to start, and has locked itself out for safety.
Why it happens: This fault occurs when the boiler's internal computer stops the system because it hasn't received the correct electrical signal to start or has detected a failure in the ignition sequence. The most common reasons include a lack of communication from your wall thermostat, a failure in the electronic control board, or a component like the gas valve not opening to allow the flame to light.
Check that your room thermostat and programmer are turned up and calling for heat.Ensure the gas supply to the property is turned on.Turn the boiler temperature control knob to the 'Off' position, wait 10 seconds, then turn it back to your desired setting to attempt a reset.
Your boiler has automatically shut down for safety because it has become dangerously too hot, or because the flue is blocked and exhaust gases cannot escape properly.
Full guide for Red LED illuminatedYour boiler is operating exactly as it should and is currently burning gas to heat your water or home.
Full guide for Green 'Flame' ledon the Potterton Kingfisher MF RSL/CFL
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