High
D1 286 on Worcester Bosch Greenstar 12i System

Your boiler has detected that the water returning to it is too hot, causing it to shut down to prevent damage from overheating.

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

Return temperature too high - Boiler overheat

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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