High Lockout
2940 on Worcester Bosch Greenstar 8000 Life/Style

Your boiler has detected an internal communication error or hardware fault within its main control system, preventing it from firing up 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

System fault burner control unit

What causes this fault?

This fault occurs when the boiler's internal computer and the burner control system stop talking to each other reliably. The most common reason is a electronic failure on the main circuit board or a loose connection in the internal wiring, which means the boiler can no longer safely regulate the flame.

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

2963View →2965View →

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