Viessmann 69 Fault Code
The Viessmann 69 fault code means: your boiler is having trouble detecting the flame used to heat your water, which is causing it to shut down for safety.. It appears on 1 Viessmann model in our database.
Technical description: Ionisation current outside permissible range (second variant)
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 69 fault code
Click a model for the full fault code list and model-specific repair notes.
Source
Viessmann 69 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