F.57 High

Vaillant F.57 Fault Code

Also written as F57 — same fault.

The Vaillant F.57 fault code means: your boiler has detected that a key ignition component is wearing out, meaning it is struggling to reliably start the flame needed to heat your home.. It appears on 1 Vaillant 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: Fault:Measuringprogram Activecomfortprotectionmodehasdetectedaregulationfault – Ignitionelectrodehighlycorroded
Typical repair cost £150-250 (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.57 fault code

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

Source

Vaillant F.57 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 27 April 2026