High
2931 on Worcester Bosch 1000

The internal computer in your boiler has encountered a major software error and has stopped operating to prevent further damage.

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

Illegal instruction executed by microcontroller

What causes this fault?

Software error

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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