BoilerFaultCodesThe 6 most common faults
Your boiler has stopped working because the water pressure inside the heating system has dropped too low to operate safely.
Locate the filling loop, which is a silver braided hose under your boiler.Open the valves at both ends of the hose to let water into the system.Watch the pressure gauge on the front of the boiler until the needle reaches 1.5 bar, then turn the valves off securely.
Your boiler has lost the water pressure required to circulate heat around your home.
Locate the external filling loop, which is usually a flexible silver hose connected to the water pipes underneath the boiler.Open the valves on the filling loop to allow cold water into the system until the pressure gauge reads between 1.0 and 1.5 bar.Close both valves tightly and remove the filling loop if specified by your manual to prevent backflow.
Your boiler has become too hot and has shut itself down as a safety precaution to prevent damage.
Check that all radiator valves are fully open to allow water to circulateEnsure the system pressure is between 1 and 1.5 bar on the pressure gaugePress and hold the reset button for 2 seconds to see if the fault clears
Your boiler has switched itself off because it got too hot and needs to cool down before it can be restarted.
Wait for the boiler to cool down naturally until the three horizontal lines disappearCheck that your radiator valves are open and not turned offEnsure your system pressure is topped up to roughly 1.5 bar on the gaugePress the 'Reset' button once the temperature has dropped
Your boiler has shut down because the burner failed to light or stay lit, requiring a manual reset to try and fire up again.
Locate the reset button or dial on the front control panel.Press or turn the control to the 'Reset' position for 5 seconds.Wait for the boiler to attempt the ignition sequence; if it fails again, contact a Gas Safe engineer.
Your boiler has stopped running for safety reasons because it failed to light or stay lit during operation.
Check if your gas supply is active by testing another gas appliance like a hob.Ensure there is credit on your gas meter if you have a prepaid system.Press the 'Reset' button on the front of the boiler for two seconds.
on the Ideal Icos
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 Ideal 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