High Lockout
b1 on Worcester Bosch Greenstar 30HE

Your boiler's internal computer is having trouble communicating with its identity chip, meaning it doesn't recognize its own settings.

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

Coding plug not detected.

What causes this fault?

This fault occurs when the boiler's main control board loses its connection to a small electronic chip that tells the unit exactly how to operate. The most common reason is a loose connection or a component failure on the circuit board, often caused by natural vibrations or moisture getting into the internal components over time.

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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