High
2966 B on Worcester Bosch Greenstar 8000 Life

Your boiler is overheating because water is not circulating through your heating system fast enough, likely due to low pressure or a blockage.

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 temperature rise in heat exchanger too rapid 1. System is not filled with water. 2. No water flow, because CH system is closed. 3. No water flow, because pump is not operating correctly.

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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Related fault codes

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