BoilerFaultCodesThe 6 most common faults
Your boiler is not receiving any electrical power, so the main power light remains off and the unit cannot start.
Check if your home's main electrical consumer unit has a tripped circuit breaker.Ensure the boiler's fused spur switch (usually near the boiler) is turned on.Check if your external room thermostat or programmer is set to 'On' and has power.Check the fuse in the boiler's power switch (only if comfortable changing a standard plug-style fuse).
Your boiler has detected that the internal fan or air pressure system is sticking in the 'on' position, preventing it from starting its safety checks.
Full guide for Neon l1Your boiler has lost power or has suffered an internal electrical failure that is preventing it from starting up.
Full guide for l2Your boiler has detected that the internal fan system is stuck or hasn't cleared out old air before starting, which prevents the burner from igniting for safety.
Full guide for Neon 1Your boiler is correctly receiving a signal from the thermostat that the house needs heat, but it has not yet started the ignition process to fire up.
Check that the room thermostat is turned up higher than the current room temperatureEnsure any external programmers or timers are set to 'On' or 'Auto'Wait a few minutes to see if the boiler begins its normal start-up sequence
Your boiler is currently trying to light the gas burner with a spark, which is a normal part of the starting process.
Check if your gas supply is active at the meterMonitor the light; it should stop flashing once the boiler successfully lightsIf it continues flashing without the boiler firing up, try resetting the boiler
on the Ideal Classic NF30–NF80
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