High Lockout
Neon3 on Ideal Classic FF 330

Your boiler has lost power to its main control board, which means the system cannot operate or provide heating and hot water.

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

Main supply to PCB 25B.

What causes this fault?

This fault occurs when the link between the boiler's external controls and its internal brain is broken, preventing electricity from reaching the main control board. The most common reason is a component failure on the board itself or a blown internal fuse, which acts as a safety measure if there has been an electrical surge. In some cases, loose or damaged wiring between the components can also stop the power flow.

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.

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Related fault codes

Neon 1View →Neon 2View →

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