BoilerFaultCodesThe 6 most common faults
Your boiler has stopped working because the water pressure inside the pipes has dropped too low.
Locate the filling loop (usually a silver flexible hose) underneath the boiler.Slowly open the one or two small valves on the hose until you hear water flowing.Watch the pressure gauge and close the valves tightly once the needle reaches between 1.0 and 1.5 bar.
Your boiler has failed to light the gas, meaning your heating and hot water will not work until the system is reset or repaired.
Check that your gas emergency control valve is in the 'on' positionPre-payment meter users should check if they have enough creditPress and hold the 'R' reset button for 5 seconds to restart the ignition sequence
Your boiler has sensed it is getting too hot and has shut itself down as a safety precaution.
Check that all radiator valves are fully open to allow water to flow.Ensure there is enough pressure in the system by checking the gauge is between 1 and 1.5 bar.Try resetting the boiler by turning the selector dial to the reset position for a few seconds.
Your boiler has detected that there is not enough water in the central heating system to operate safely.
Locate the filling loop (usually two blue or black levers) underneath the boiler.Slowly open both levers until you hear water flowing into the unit.Monitor the pressure gauge until it reaches between 1.0 and 1.5 bar, then close both levers tightly.If the boiler does not restart automatically, press the 'Reset' button.
Your boiler is failing to light the gas or cannot detect that it has lit, meaning it has shut down for safety.
Check if other gas appliances, like a hob, are working to ensure gas is reaching the property.Ensure your gas meter has credit if you use a prepay system.Check that the condensate pipe (the plastic pipe going outside) is not frozen during cold weather.Press the 'Reset' button on the boiler control panel.
Your boiler has overheated, causing a safety switch to trigger and shut down the system to prevent damage.
Allow the boiler to cool down for at least 20 minutes.Check that all radiator valves are open and that your system pressure is between 1.0 and 1.5 bar on the gauge.Press the 'Reset' button on the boiler control panel once to clear the fault code.
on the Sime Giulia 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 Sime 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
Avoid the next call-out bill
Monthly cover means no unexpected bills when your boiler breaks down.
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