BoilerFaultCodesThe 6 most common faults
Your boiler has completely lost power, meaning the display and all internal functions have shut down.
Check that the main fused spur switch next to the boiler is turned on.Go to your home's fuse box or consumer unit to check if the boiler circuit breaker has tripped, and reset it if necessary.Check that the plug (if applicable) is securely plugged into the socket.
Your boiler has switched itself off because it has become too hot to operate safely.
Check that your radiator valves are open to allow water to flow.Wait for the boiler to cool down completely.Press the reset button once to see if the system restarts.
Your boiler has failed to light the gas or cannot stay lit, meaning your heating and hot water have stopped working.
Check if your gas supply is active by testing another gas appliance like a hob.Ensure your credit is topped up if you have a pre-payment gas meter.Press the reset button on the boiler control panel for 5 seconds.
Your boiler is receiving a signal for heating or hot water, but the burner is failing to ignite.
Full guide for FAULT POINT BYour boiler is attempting to start up, but the burner is only partially lighting or failing to stay fully lit.
Full guide for FAULT POINT CYour boiler has completely stopped working and locked itself out as a safety precaution, meaning you currently have no heating or hot water.
Full guide for FAULT POINT Don the Worcester Bosch 15 CBi
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