BoilerFaultCodesThe 6 most common faults
Your boiler has stopped working because the water pressure inside the system has dropped too low to operate safely.
Locate the filling loop (a silver flexi-hose with valves) underneath the boiler or nearby pipework.Open the valves slowly to allow mains water into the system while watching the pressure gauge on the front of the boiler.Stop filling once the needle reaches 1.5 bar on the gauge and ensure both valves are firmly closed.
Your boiler has stopped working because it cannot light the flame or the internal drainage pipe is blocked.
Check if the white plastic pipe underneath the boiler is frozen or blockedThaw any frozen external pipes with warm (not boiling) water or a heat padLocate your gas meter to ensure the gas supply is turned onPress and hold the Reset button for five seconds
Your boiler has effectively switched itself off because it has detected it is getting too hot, likely due to a circulation or blockage issue.
Check that your home's radiator valves are fully open.Ensure the boiler pressure is between 1 and 1.5 bar on the gauge.Attempt to reset the boiler using the selector switch.
Your boiler has stopped working because the water pressure is too low or the pump that circulates water around your home is struggling to move.
Check the pressure gauge on the front of the boiler; if it is below 1.0 bar, use the filling loop handles to top it up to 1.5 bar.Ensure all radiator valves are open to allow water to flow.Restart the boiler once the pressure is restored.
Your boiler has lost the ability to accurately measure the temperature of the water circulating through your radiators, so it has safely shut itself down to prevent overheating.
Full guide for E20Your boiler's computer module has been identified as the wrong type for your specific heating system, preventing it from operating correctly.
Full guide for E28on the Main Ecoinstaller 2
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 Main 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