High
278 F0 on Worcester Bosch Greenstar 12i System

Your boiler's computer has detected that one of its internal sensors is sending back confusing or missing information, so it has shut down as a precaution to prevent system errors.

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

Sensor test failed

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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