BoilerFaultCodesThe 4 most common faults
Your boiler is failing to light the gas to start the heating and hot water process, likely due to a temporary interruption in the gas supply.
Check if other gas appliances in your home, like a hob, are working to confirm your gas supply is active.Ensure your gas meter has credit if you are on a prepay system.Press the Reset button on the boiler control panel for 2 seconds.
Your boiler has switched itself off because it has reached a temperature that is too high, often caused by low water pressure or air trapped in the system.
Check the pressure gauge and refill the system to 1.0 bar if it is too lowBleed all radiators to remove trapped air and ensure all radiator valves are fully openPress the reset button on the boiler control panel
Your boiler has detected that the water pressure inside the heating system is too low to run safely, causing it to shut down temporarily.
Locate the filling loop (braided silver hose) usually found underneath the boiler.Slowly open the valves until the pressure gauge reaches between 1.0 and 1.5 bar.Close the valves tightly and bleed your radiators to remove any trapped air.
Your boiler has started an ignition sequence but the flame has gone out, meaning the system has shut down as a safety precaution.
Check that your gas emergency control valve is open and you have credit on your meterCheck if other gas appliances in your home, such as a hob, are working correctlyReset the boiler by pressing the 'Restart' button for two seconds
on the Keston Combi 30
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 Keston 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