BoilerFaultCodesThe 6 most common faults
Your boiler has detected that there is not enough water in the system to operate safely and has shut down as a precaution.
Locate the filling loop (the flexible silver hose) underneath the boiler.Slowly open the one or two taps on the filling loop until you hear water entering.Monitor the pressure gauge and close the taps once the needle reaches between 1.0 and 1.5 bar.
Your boiler has tried to light itself three times but failed, meaning your heating and hot water have stopped working.
Check if your gas meter has credit and the isolation valve is open.Ensure other gas appliances in your home, like a hob, are working correctly.Press the Reset button on the boiler control panel to clear the lockout.
Your boiler has stopped working because the water pressure inside the heating system has dropped too low.
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.
Your boiler is struggling to move water around the system fast enough, likely due to low water pressure or a blockage.
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
Your boiler has lost the ability to accurately measure the temperature of the water returning to it, so it has shut down as a precaution to prevent overheating.
Full guide for F01Your boiler's internal thermometer is not sending a proper signal, so the system has stopped heating your water to prevent it from overheating.
Full guide for F10on the Heatline Capriz Plus
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