BoilerFaultCodesThe 6 most common faults
Your boiler has stopped working because it has detected a general internal error and has locked itself out for safety.
Locate the reset button on the front control panelPress and hold the reset button for 3 to 5 secondsWait for the boiler to restart and check if the error clears
Your boiler has tried to light itself several times without success and has now locked itself out for safety.
Check if your gas meter has credit and the emergency control valve is openCheck if other gas appliances, like a cooker, are working correctlyPress and hold the reset button for five seconds to see if the boiler restarts
Your boiler has detected that the water pressure in the central heating system is too low to operate safely.
Locate the silver braided filling loop hoses underneath or near your boiler.Slowly open the valves on the filling loop until you hear water entering the system.Watch the pressure gauge and close the valves tightly once the needle reaches 1.5 bar.
Your boiler has stopped working because it cannot detect any water pressure in the system.
Locate the pressure gauge on the front of the boiler or underneath on the pipework.If the needle is below 1 bar, locate the filling loop (the silver flexible hose with two small valves).Open both valves slowly to let water into the system until the gauge reaches 1.5 bar, then close them tightly.Turn the boiler off and back on to reset the fault code.
Your boiler has failed to light after several attempts and has locked itself out for safety reasons.
Check that your gas supply is turned on at the meterIf you have a prepaid meter, ensure you have credit availablePress and hold the 'Reset' button for 5 seconds to try restarting the boiler
Your boiler has switched itself off because it has become too hot inside, often due to a blockage or a circulation problem.
Check that all radiator valves are fully openEnsure the system water pressure is between 1 and 1.5 barPress the 'Reset' button on the control panel to see if the fault clears
on the Johnson Starley Comet 80
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 Johnson Starley 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