S.96 Low

Viessmann S.96 Fault Code

Also written as S96 — same fault.

The Viessmann S.96 fault code means: your boiler is currently idle because it is waiting for a signal from an external device or a specific room control that is not currently requesting heat.. It appears on 1 Viessmann model in our database.

Monitor it

This is a minor fault. Keep an eye on it and mention it at your next annual boiler service. Reset the boiler and see if it clears.

Technical description: No demand, external hook-up, heating circuit 3

Engineer required

This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.

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Viessmann models that show the S.96 fault code

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

Source

Viessmann S.96 fault code information on this page is sourced and cross-checked against the official Viessmann service / installation manuals for each affected model.

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