F.074 High

Vaillant F.074 Fault Code

Also written as F074 — same fault.

The Vaillant F.074 fault code means: your boiler's internal sensor that detects water pressure has lost its electrical connection, so the system can no longer confirm it is safe to operate.. It appears on 3 Vaillant models 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: Fault in the electrical connection for the water pressure sensor. The signal for the water pressure sensor has been interrupted.
Typical repair cost £120-220 (including labour)

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.074 fault code

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

Source

Vaillant F.074 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