High
266 CE on Worcester Bosch Greenstar 12i System

Your boiler is struggling to detect water moving through the system, which prevents it from heating your home 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

No pressure variation detected after switching pump

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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