High Lockout
oF on Ideal Logic Combi C24 C30 C35

Your boiler is in a standby or programming mode and thinks it has been told to stay switched off.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed

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

PCB Programming - Off state

What causes this fault?

This fault occurs when the boiler's internal computer has been set to a software-off state, often following a power cut or a manual adjustment in the programming menu. Instead of a mechanical breakdown, the boiler has essentially 'forgotten' it should be running and is stuck in a standby mode. In some cases, this can also happen if the main circuit board has a glitch and requires a professional reconfiguration.

Engineer required

This is a high severity fault. Stop using the boiler and call a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.

Find a Gas Safe engineer
Search the official register →

Related fault codes

F2View →L2View →

Related guides you might find useful

Boiler keeps cutting out

Lockout fault with a reset-needed pattern.

Read →

When to replace your boiler

7 signs repair isn't worth it anymore.

Read →

Is boiler cover worth it?

Break-even maths on monthly cover.

Read →