What does the Viessmann Vitodens 100-W F87 fault code mean?
The F87 fault code on the Viessmann Vitodens 100-W indicates an issue with faulty insulation, which can lead to overheating and potential damage to the boiler. This fault typically requires immediate attention to ensure safe operation and prevent further complications.
Common Causes
- Damaged Insulation: Physical damage to the insulation material can compromise its effectiveness, leading to overheating.
- Moisture Ingress: Water or moisture entering the insulation can cause it to degrade, resulting in insufficient thermal protection.
Can I fix it myself? (DIY)
It is highly recommended to call a Gas Safe Engineer for this issue, as it involves critical components of the boiler that require professional expertise to ensure safety and compliance with regulations.
Estimated Repair Cost (2026 UK Prices)
The estimated repair cost for addressing the F87 fault due to faulty insulation is approximately £250 to £400. This includes the cost of replacing insulation materials and any necessary labour, reflecting the complexity of the repair.