High
2964 B on Worcester Bosch 26 CDi Xtra

Your boiler has detected that water isn't moving through the system fast enough to safely carry heat away, so it has shut down to prevent 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

Flow rate in heat exchanger is too low

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

A7View →E9View →224VView →

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