What does the Viessmann Vitodens 111-W F87 fault code mean?
The F87 fault code on the Viessmann Vitodens 111-W indicates a problem with the heating circuit diagnostics. This typically suggests that the boiler is unable to properly monitor or control the heating system, which can affect performance and efficiency.
Common Causes
- Faulty Temperature Sensor: A malfunctioning temperature sensor can lead to incorrect readings, causing the boiler to display the F87 fault code.
- Wiring Issues: Damaged or loose wiring connections within the heating circuit can disrupt communication between components, triggering the fault code.
Can I fix it myself? (DIY)
It is recommended to call a Gas Safe Engineer for any gas or electrical issues related to the boiler. However, you can check the pressure gauge and ensure it is within the normal range (1-1.5 bar) and reset the boiler if necessary.
Estimated Repair Cost (2026 UK Prices)
The estimated repair cost for resolving the F87 fault code could range from £150 to £300, depending on whether a temperature sensor needs replacing or if wiring repairs are required. This estimate includes parts and labour.