BoilerFaultCodesIdeal L 0C Fault Code
Also written as L0C — same fault.
The Ideal L 0C fault code means: your boiler is repeatedly shutting down and trying to restart itself, likely due to an underlying component failure preventing reliable ignition.. It appears on 3 Ideal models in our database.
Technical description: Restart occurs 5 times within 15 minutes.
What causes the Ideal L 0C fault?
This fault occurs when the boiler senses a repeated failure to maintain a steady flame, causing it to shut down and attempt to restart itself five times in a short period. The most common reason is that the internal sensors or gas components are struggling to confirm a safe ignition, eventually leading the system to lock itself out for safety.
DIY fix possible
Turn the power to the boiler off at the fused spur switch (the wall switch).Wait for at least 5 minutes to allow the internal timer to reset.Turn the power back on and wait for the boiler to complete its start-up sequence without pressing the reset button.
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Gas Safe Register →Ideal models that show the L 0C fault code
Click a model for the full fault code list and model-specific repair notes.
Source
Ideal L 0C fault code information on this page is sourced and cross-checked against the official Ideal service / installation manuals for each affected model.
Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed 27 April 2026