BoilerFaultCodesThe 6 most common faults
Your boiler has temporarily stopped working because the water pressure inside the heating system has dropped too low.
Locate the filling loop connected to your boiler or under the sink.Open the valves slowly to let water into the system until the pressure gauge reads between 1.0 and 1.5 bar.Close the valves firmly and check the display to see if the error clears.
Your boiler has tried to light several times but has been unable to detect a flame, causing the system to shut down for safety.
Check if your gas supply is active by testing other gas appliances like a hobEnsure your gas meter has credit if you use a pre-payment meterPress and hold the 'Reset' button for five seconds to see if the boiler restartsCheck that the condensate pipe (outside white plastic pipe) isn't frozen if the weather is very cold
Your boiler's internal computer has encountered a software or electronic error and can no longer control the heating properly.
Press the 'Reset' button on the front of the boiler once.If it does not reset, turn the power supply to the boiler off at the fused spur switch.Wait 60 seconds and then turn the power back on.
Your boiler is struggling to clear exhaust gases before ignition, so it has paused itself to ensure it is safe to operate.
Full guide for 205Your boiler is currently locked in a testing mode used by engineers to check the flue system, which prevents it from heating your home normally.
Full guide for 208Your boiler has temporarily stopped working because it has detected a blockage or a safety issue with the airflow and exhaust gases.
Full guide for 210on the Worcester Bosch Greenstar 30i System Compact ErP
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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