BoilerFaultCodesViessmann F0 Fault Code
The Viessmann F0 fault code means: your boiler has stopped working because its internal computer and burner system have detected a technical communication failure.. It appears on 9 Viessmann models in our database.
Technical description: Burner blocked - Internal error
What causes the Viessmann F0 fault?
This fault occurs when the boiler's main control board loses the ability to communicate with the internal burner firing system. It is usually caused by a hardware failure within the electronic control unit (PCB) or a loose connection in the wiring harness that links these critical components. Because the computer cannot safely verify the burner's status, it shuts the system down to prevent an unsafe start-up.
Engineer required
This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.
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Gas Safe Register →Viessmann models that show the F0 fault code
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Source
Viessmann F0 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