High
E2 223 on Worcester Bosch Greenstar 12i System

Your boiler is struggling to detect water moving through it, meaning it has switched off to protect itself and will not provide heating or hot water until the issue is resolved.

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

Flow sensor open circuit - Flow sensor disconnected or damaged.

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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