High
258 on Worcester Bosch 1000

Your boiler's internal computer is experiencing a temporary software glitch and has shut down to prevent any unsafe operation.

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

Internal watchdog error

What causes this fault?

System monitoring fault

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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