BoilerFaultCodesThe 6 most common faults
Your boiler is unable to light the flame after several attempts, which means it cannot provide any heating or hot water until the issue is resolved.
Check that your gas emergency control valve is in the open positionEnsure other gas appliances in your home, such as a hob, are working correctlyCheck if you have credit on your gas meterReset the boiler by pressing the ‘RESET’ button for two seconds
Your boiler has got too hot and has shut itself down as a safety precaution to prevent damage.
Check that the boiler pressure is between 1.0 and 1.5 bar on the gaugeEnsure all radiator valves and zone valves are openBleed your radiators to remove any trapped air from the systemReset the boiler after performing these checks
Your boiler is having trouble detecting the correct amount of water inside the system, preventing it from running safely.
Check the pressure gauge on the front of the boiler; it should be between 1.0 and 1.5 bar.If the pressure is too low, use the external filling loop to top up the water level.Restart the boiler once the correct pressure is reached to see if the code clears.
Your boiler has started an ignition sequence but the flame keeps going out, meaning it cannot stay lit to provide heat or hot water.
Check the white plastic condensate pipe outside for signs of ice or blockages and defrost with warm water if frozen.Inspect the flue and air intake terminals on the outside wall to ensure they are not blocked by debris or foliage.If you use LPG, verify that your tank has not run out of fuel.
Your boiler has detected that the water pressure is too low to operate safely and has shut down as a precaution.
Locate the filling loop (the flexible silver hose) underneath or near the boiler.Slowly open the one or two 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 between 1.0 and 1.5 bar.
Your boiler has switched off because there is too much water pressure in the system, which can put unnecessary strain on the internal seals.
Check that the filling loop valves are fully closed and not leakingBleed water from a radiator using a bleed key to lower the system pressureMonitor the pressure gauge until it returns to between 1 and 1.5 barReset the boiler once the correct pressure is reached
on the Keston System S30
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