High Lockout
9C on Ideal Maximiser SE

Your boiler's main control board has lost communication with its internal memory chip, meaning it cannot process the settings needed to run safely.

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

Control panel not able to detect BIM.

What causes this fault?

This fault happens when the boiler's main control board loses its connection to a small plug-in memory chip called the BIM, which holds the boiler's specific identity and settings. It is usually caused by a loose connection, a failed electronic component on the circuit board, or the memory chip itself becoming faulty or corrupted. Without this vital data, the boiler cannot verify which model it is and shuts down as a safety precaution.

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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