BoilerFaultCodesThe 6 most common faults
01
F22 High DIY-safe
Your boiler has stopped working because the water pressure inside the heating system has dropped too low.
What to try first
Locate the filling loop (a silver flexible hose) underneath the boiler.Open the small valve or tap on the loop to allow mains water into the boiler.Monitor the pressure gauge on the front until it reaches 1.5 bar, then turn the valve firmly off.
02
F24 High DIY-safe
Your boiler is struggling to move water around the system fast enough, likely due to low water pressure or a blockage.
What to try first
Check your boiler pressure gauge; if it is below 1 bar, use the filling loop to top it up to 1.5 barEnsure all radiator valves are fully openTurn the boiler off and back on again to reset the temporary fault
03
F28 High Engineer
Your boiler is trying to start but the flame is not catching, meaning it cannot provide you with heating or hot water.
Full guide for F2804
F00 High Engineer
Your boiler has lost the ability to measure the temperature of the water being sent to your radiators, so it has shut down as a precaution to prevent overheating.
Full guide for F0005
F01 High Engineer
Your boiler has stopped working because it is unable to accurately measure the temperature of the water returning to it from your radiators.
Full guide for F0106
F10 High Engineer
Your boiler has stopped working because it is unable to accurately measure the temperature of the water circulating through your heating system.
Full guide for F10on the Heatline Vizo 28
Filling loopPressure relief valvePressure sensorCentral heating pumpSystem filterIgnition lead
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 Heatline 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