Fault Code Guide

Vaillant Fault Code Guide — Every F-Code & S-Code Explained

Complete reference for all Vaillant boiler error codes — F-codes (faults) and S-codes (status). Vaillant ecoTEC error codes explained. Find your code, understand the cause, and get it fixed.

Gas safety emergency? If you smell gas or suspect a gas leak, do not use any electrical switches. Call the National Gas Emergency Service on 0800 111 999 immediately and leave the property. Do not call VaillantCare — call the gas emergency line first.
Free download: The Vaillant owner’s guide to fault codes & when to replace — by email, no booking needed. Get the free guide

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