BoilerFaultCodesViessmann F.517 Fault Code
Also written as F517 — same fault.
The Viessmann F.517 fault code means: your boiler is struggling to communicate with its external control panel or thermostat, which may prevent it from receiving instructions to turn on your heating or hot water.. It appears on 4 Viessmann models in our database.
Technical description: Control mode, remote control unit not functioning
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 F.517 fault code
Click a model for the full fault code list and model-specific repair notes.
Source
Viessmann F.517 fault code information on this page is sourced and cross-checked against the official Viessmann service / installation manuals for each affected model.
- Viessmann Vitodens 100-W WB1A manual (PDF)
- Viessmann Vitodens 200-W B2HF System manual (PDF)
- Viessmann Vitodens 200-W B2KF Combi manual (PDF)
Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed 7 July 2026