BoilerFaultCodesViessmann 95:0 Fault Code
Also written as 950 — same fault.
The Viessmann 95:0 fault code means: your boiler has lost its connection to its remote communication module, meaning you cannot control your heating via the app, but your hot water and heating should still work manually.. It appears on 5 Viessmann models in our database.
Technical description: Without Vitocom 100 communication interface
What causes the Viessmann 95:0 fault?
This fault occurs when the boiler's main control board expects to be talking to an external communication module, like a Vitocom 100, but cannot find it on the system. The most common reason is a loose or damaged data cable between the module and the boiler, or the internal communication component has lost power and stopped sending a signal.
DIY fix possible
Check that your internet router is switched on and workingEnsure the Vitocom 100 module is plugged in and has powerIdentify if the communication cable between the boiler and the module has become loose
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Gas Safe Register →Viessmann models that show the 95:0 fault code
Click a model for the full fault code list and model-specific repair notes.
Source
Viessmann 95:0 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