Medium
CA on Worcester Bosch Greenstar 30si

Your boiler has detected that the water is flowing through your hot water system faster than it can heat up, which often points to an issue with how much water is being drawn from your taps.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed

Book a service

This fault should be looked at by a Gas Safe engineer within the next week or two. It may get worse if left.

What the manual says

Manufacturer manual

Flow rate through the DHW heat exchanger too high

From this model's manual
Verified against the Worcester Bosch Greenstar 30si 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 fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.

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