BoilerFaultCodesThe 6 most common faults
Your boiler has tried to light several times but failed to ignite, so it has safely shut itself down for your protection.
Check that your gas supply is turned on and other gas appliances like the hob are working.Check your prepayment gas meter if you have one to ensure you haven't run out of credit.Locate the reset button on your boiler and press it firmly for about 5 seconds to attempt a restart.
Your boiler has detected a critical internal error that caused it to shut down for safety reasons and will not restart on its own.
Full guide for Fast flashYour boiler requires a specific installation or commissioning step to be completed before it will unlock and allow normal operation.
Full guide for N/AYour boiler has detected that the flue is getting too hot and has automatically shut down to keep your home safe.
Full guide for Slow flash (normally on, flashes off)Your boiler has been left in its internal testing mode, which is usually only used by engineers during a service or setup.
Locate the horizontal dial on the front of the boiler control panel.Check if the dial is turned all the way to the right (maximum position).Turn the dial back to your desired temperature setting to exit service mode.
Your boiler has been left in a manual testing mode after a service or inspection and needs to be switched back to its normal operating setting.
Locate the service mode switch (or dial) on the boiler control panel.Ensure the switch is moved from the 'Min' or 'Service' position back to the 'Normal' or 'Off' position.Perform a simple reset by pressing the reset button to clear the flashing light.
on the Worcester Bosch Greenstar
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 Worcester Bosch 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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