High
2966 B on Worcester Bosch Greenstar 8000 Life Regular

Your boiler has detected that it is heating up far too quickly, likely because water is not flowing through the system as it should.

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.

What the manual says

Manufacturer manual

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.

From this model's manual
Verified against the Worcester Bosch Greenstar 8000 Life Regular installation & service manual.
Plain-English guidance below. Severity, DIY steps, costs and parts are our interpretation to help you act, not text from the manual.

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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