BoilerFaultCodesThe 6 most common faults
Your boiler has detected that there isn't enough water moving through the system, which is usually caused by a leak or a pump that has stopped working.
Check for any visible water leaks around the boiler or radiatorsCheck your pressure gauge and top it up to 1.5 bar using the filling link if it is lowRestart the boiler to see if the pump clears itself
Your boiler has shut down because it has detected that the water inside is getting too hot or the pressure is incorrect.
Check the pressure gauge on the front of the boiler is between 1 and 1.5 barTop up the water pressure using the filling link if it is too lowEnsure all radiator valves are fully open and there are no blockagesPress and hold the reset button for five seconds
Your boiler is failing to light the gas flame and has locked itself out as a safety precaution.
Check if your gas meter has credit and the isolation valve is openCheck if other gas appliances in your home, like a hob, are working correctlyPress the Reset button on the boiler control panel for five seconds
Your boiler has sensed that the water inside is getting too hot and has shut down as a safety precaution.
Check that all radiator valves are fully openEnsure the boiler pressure is between 1.0 and 1.5 barReset the boiler using the reset button
Your boiler has tried to light several times but cannot detect a stable flame, so it has shut down for safety.
Check if other gas appliances in your home, like a hob, are working to ensure gas is reaching the property.Ensure your gas emergency control valve (usually by the meter) is in the 'on' position.If it is freezing outside, check that your white plastic condensate pipe is not frozen or blocked.Press and hold the 'Reset' button for five seconds to see if the boiler restarts.
Your boiler has lost its connection to the electrical supply or has detected an issue with the power coming into the unit.
Check if there has been a local power cut or if a fuse has tripped in your home's main consumer unit.Ensure the boiler's dedicated power switch (usually a fused spur near the boiler) is turned on.Press and hold the reset button for five seconds once power is restored.
on the Worcester Bosch 26 CDi Xtra
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