How much does it cost to fix Vaillant error code D.098?

Typical repair cost for the Vaillant D.098 fault is £120-200 including labour.

D.098 High

Vaillant D.098 Fault Code

Q: What does the Vaillant D.098 fault code mean?

Your boiler has lost communication with a small plug-in component that tells it exactly which model it is, meaning it cannot operate until this identity connection is restored.

Also written as D098 — same fault.

The Vaillant D.098 fault code means: your boiler has lost communication with a small plug-in component that tells it exactly which model it is, meaning it cannot operate until this identity connection is restored.. It appears on 3 Vaillant models in our database.

Technical description: Codingresistorvalue

Typical repair cost £120-200 (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 D.098 fault code

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

Source

Vaillant D.098 fault code information on this page is sourced and cross-checked against the official Vaillant service / installation manuals for each affected model.

Vaillant ecoTEC Plus 836 manual (PDF)

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