High
E9 on Worcester Bosch Greenstar 28CDi

Your boiler has detected that it is getting too hot and has automatically switched itself off to prevent any damage or danger.

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

Safety temperature limiter (primary heat exchanger) or flue gas temperature limiter has operated

From this model's manual
Verified against the Worcester Bosch Greenstar 28cdi Compact 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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