BoilerFaultCodesThe 6 most common faults
Your boiler has shut down because a specific internal component has become too hot, usually due to a lack of water flow or a circulation blockage.
Check that your central heating valves and radiator valves are fully open.Ensure your system water pressure is within the green zone (typically 1.0 to 1.5 bar).Press the reset button on the front control panel to see if the boiler restarts.
Your boiler is failing to light the gas flame despite several attempts, meaning you currently have no heating or hot water.
Check that your gas supply is turned on at the meterIf you have a pre-payment meter, ensure you have credit remainingIf it is freezing outside, check that your white condensate pipe is not frozen or blockedPress the 'Reset' button on the front panel to restart the ignition sequence
Your boiler has switched itself off because it has reached an unsafe temperature and needs to cool down.
Check that your radiator valves are open and not turned to zero.Ensure there is enough water pressure in the system (typically 1.0 to 1.5 bar).Press the 'Reset' button on the front of the boiler to see if the code clears.
Your boiler has lost water pressure, causing it to shut down to prevent damage to the internal components.
Locate the pressure gauge on the front of the boiler or underneath it.Find the filling loop (usually a silver flexible hose with two small valves).Slowly open both valves to let water into the system until the gauge reaches 1.5 bar, then close them tightly.The boiler should restart automatically or may require a reset.
Your boiler has stopped working because the water pressure is likely too low to operate safely.
Locate the pressure gauge on your boiler or pipeworkCheck if the needle is below the 1 bar markIf low, use the external filling loop valves to top up the water until the gauge reads between 1 and 1.5 barRestart the boiler to see if the code clears
Your boiler is struggling to keep its flame lit or cannot detect the flame, so it has safely shut itself down to prevent gas from building up.
Full guide for L Fon the Ideal Icos 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 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