BoilerFaultCodesThe 6 most common faults
Your boiler is struggling to circulate water properly, causing the flame to cut out shortly after it starts to prevent overheating.
Check the pressure gauge on the front of the boiler; it should be between 1.0 and 1.5 bar.If the pressure is too low, use the filling loop valves to top the system up with water.Ensure all radiator valves and boiler isolation valves are fully open.
Your boiler has detected that there is not enough water flowing through the system or there is a lack of pressure to operate safely.
Check the pressure gauge on the front of the boiler; it should be between 1 and 1.5 bar.If the pressure is too low, use the filling loop valves under the boiler to top it up.Check that all radiator valves and boiler isolation valves are fully open.Ensure all radiators have been bled to remove trapped air.
Your boiler has no power and the screen is completely blank, meaning it cannot provide any heating or hot water until electrical flow is restored.
Check if other appliances or lights in your home are working to rule out a general power cut.Inspect your home's main consumer unit (fuse box) to see if a circuit breaker has tripped.Check the fused spur switch located next to your boiler; ensure it is turned on and try replacing the 3-amp fuse inside.
Your boiler has stopped working because a sensor that monitors water temperature has failed, preventing the system from firing up.
Full guide for 12Your boiler has stopped working because its internal safety sensors can no longer monitor the temperature of the exhaust gases.
Full guide for 13Your boiler has stopped working because a temperature sensor on the pipework is broken or sends an incorrect signal, preventing the burner from lighting.
Full guide for 16on the Halstead Dimplex Combi
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 Halstead 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