BoilerFaultCodesVaillant F.075 Fault Code
Also written as F075 — same fault.
The Vaillant F.075 fault code means: your boiler is struggling to detect the movement of water when it tries to start the heating, which usually means the internal pump is failing to spin or there is a blockage preventing flow.. It appears on 3 Vaillant models in our database.
Technical description: The pressure change is too low when the heating pump is started up.
Engineer required
This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.
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Vaillant models that show the F.075 fault code
Click a model for the full fault code list and model-specific repair notes.
Source
Vaillant F.075 fault code information on this page is sourced and cross-checked against the official Vaillant service / installation manuals for each affected model.
Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed 7 July 2026