Viessmann 07, 09 Fault Code
Also written as 0709 — same fault.
The Viessmann 07, 09 fault code means: your boiler has detected a problem with the burner and has shut itself down as a safety precaution, meaning you will not have any heating or hot water.. It appears on 5 Viessmann models in our database.
Technical description: Burner control switches to lockout
DIY fix possible
Check that you have not run out of heating oil in your storage tankEnsure the oil shut-off valve is fully openPress the reset button on the burner control unit once to see if the boiler restarts
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Gas Safe Register →Viessmann models that show the 07, 09 fault code
Click a model for the full fault code list and model-specific repair notes.
Source
Viessmann 07, 09 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