00:6 Low

Viessmann 00:6 Fault Code

Also written as 006 — same fault.

The Viessmann 00:6 fault code means: your boiler is correctly configured for your specific home heating setup, and this code is simply an information status indicating how your system is set up to manage your radiators and hot water.. It appears on 6 Viessmann models 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: System design 2, 3: 1 heating circuit without mixer A1, 1 mixer circuit M2 with DHW heating

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 00:6 fault code

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

Source

Viessmann 00:6 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 27 April 2026