High
23 on Heatline Sargon 30

Your boiler is not detecting water flowing through its pipes, which means it will stop heating your water or home to prevent damage.

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 sensor fault

Referenced from a related model
This code was carried over from a closely related model. Treat it as a guide and confirm against your boiler’s own 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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