What does the Viessmann Vitodens 100-W F86 fault code mean?
The F86 fault code on the Viessmann Vitodens 100-W indicates a faulty earth connection, which can lead to electrical safety issues and improper operation of the boiler. This fault requires immediate attention to ensure safe functioning and compliance with electrical standards.
Common Causes
- Loose Connections: A loose or corroded earth connection can disrupt the electrical grounding of the boiler.
- Damaged Wiring: Damaged or frayed wiring in the earth circuit can prevent proper grounding and trigger the fault code.
Can I fix it myself? (DIY)
It is strongly advised to call a qualified Gas Safe Engineer to address this issue, as it involves electrical components that can pose safety risks if handled improperly.
Estimated Repair Cost (2026 UK Prices)
The estimated repair cost for resolving the F86 fault could be around £150 to £250, depending on whether the issue is a simple connection fix or requires replacement of wiring components.