BoilerFaultCodesThe 6 most common faults
Your boiler has failed to light a flame because it isn't receiving the necessary electricity or gas supply to start up.
Check if other gas appliances, like your hob, are working to ensure gas is reaching the house.Check your fuse box or consumer unit to see if a circuit breaker has tripped.Press the reset button on the boiler control panel once to see if it clears the error.
Your boiler is struggling to circulate water properly or the pressure is too low, causing it to shut down shortly after lighting.
Check the pressure gauge on the front of the boiler; it should be between 1 and 1.5 bar.If the pressure is low, use the filling loop valves to top the system up with water.Ensure all radiator valves and boiler isolation valves are fully open.Restart the boiler once the correct pressure is reached.
Your boiler has detected that there is not enough water pressure or flow to operate safely, causing it to shut down shortly after lighting.
Check the pressure gauge on the front of the boiler or under the casing.If the needle is below 1 bar, use the external filling loop valves to top the system up to 1.5 bar.Ensure all radiator valves and isolation valves under the boiler are fully open.Reset the boiler once the correct pressure is reached.
Your boiler has lost all power and the control panel is completely blank, meaning it cannot operate at all.
Check if your home's main electrical consumer unit (fuse box) has tripped.Ensure the boiler's isolation switch (usually a red-fused spur near the unit) is turned on.Check if the fuse inside the boiler's external plug or switch has blown and needs replacing.
Your boiler has lost all power and the control panel is completely blank, meaning the system cannot start or provide any heating.
Check if the main boiler power switch or fused spur is turned on.Inspect your home's main consumer unit (fuse box) to see if a circuit breaker has tripped.Check the fuse in the boiler's external wall switch; it typically requires a 3-amp fuse.
Your boiler has stopped working because it cannot light the flame and is detecting a fault with one of its internal heat sensors.
Full guide for 12on the Halstead Dimplex System
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