L 0C High

Ideal 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 5 Ideal models in our database.

Call an engineer soon

Book a Gas Safe engineer within 24 to 48 hours. Your boiler may be unsafe or could break down completely if left.

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.

Typical repair cost £120-£350 (including labour)

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.

Find a Gas Safe engineer

Search the official register for a qualified engineer in your area.

Gas Safe Register →

Avoid the next call-out bill

A cover plan would handle faults like L 0C: no call-out fees, no surprise bills.

Approved partner
Domestic Appliance Guard
Unlimited call-outs, 24/7 helpline, no price-hike promise
Get a quote →

Affiliate links. We may earn a commission at no extra cost to you.

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 7 July 2026