High
No code 212 on Worcester Bosch Greenstar 12i System

Your boiler is overheating because it cannot move the hot water away from the heating unit fast enough.

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

Safety or flow temperature rises too fast

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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