BoilerFaultCodesThe 6 most common faults
Your boiler has stopped working because the water pressure inside the heating system has dropped below the required level.
Locate the internal filling link (a silver lever or rotating valve) under the bottom of your boiler.Open the valve slowly to allow water into the system until the pressure gauge on the front display reaches between 1.0 and 1.5 bar.Close the valve tightly and check that the fault code clears from the display.
Your boiler has sensed that the water temperature has risen above the level it was set to reach, leading it to shut down for safety.
Check that all radiator valves are fully open to allow water to circulate.Ensure there is enough water pressure in the system by checking the digital gauge.Restart the boiler using the reset button on the touch screen.
Your boiler is failing to light the gas even though it is trying to, which prevents your heating and hot water from working.
Check if other gas appliances (like a hob) are working to ensure gas is reaching the propertyCheck if your gas meter has credit (if using a pre-payment meter)Hold the 'Reset' button on the front of the boiler for 3 seconds
Your boiler has detected an internal electrical communication error, which means it has stopped running to prevent damage to its electronic components.
Press the 'Reset' button on the front display panel and hold for three seconds.Wait up to 10 minutes for the boiler to complete its restart sequence.Ensure your household electricity supply is stable and you have not recently had a power cut.
Your boiler has tried to start up but cannot detect a flame, meaning it cannot provide heating or hot water.
Check if other gas appliances (like a hob) are working to ensure gas is reaching the propertyCheck that your prepaid gas meter has creditTry resetting the boiler using the reset button on the touchscreen
Your boiler has sensed that the water inside is getting much hotter than it should be and has shut down as a safety precaution.
Ensure all radiator valves (TRVs) are turned to the highest settingCheck that the boiler pressure gauge is between 1 and 1.5 barReset the boiler using the display panel to see if the fault clears
on the Worcester Bosch Greenstar 8000 F
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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