No Water Flow High

Baxi No Water Flow Fault Code

Also written as NOWATERFLOW — same fault.

The Baxi No Water Flow fault code means: your boiler is struggling to move water through the system, causing it to keep restarting the pump without actually firing up the heating.. It appears on 1 Baxi model in our database.

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: Indicated by the flow switch - a continuous cycle of Pump Overrun and Anti-cycle occurs.
Typical repair cost £120-280 (including labour)

DIY fix possible

Check that the central heating valves under the boiler are fully openEnsure all radiator valves (TRVs) are turned to their highest settingGently bleed your radiators to remove any trapped air that might be blocking flow

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Baxi models that show the No Water Flow fault code

Click a model for the full fault code list and model-specific repair notes.

Source

Baxi No Water Flow fault code information on this page is sourced and cross-checked against the official Baxi service / installation manuals for each affected model.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed 7 July 2026