What does the Viessmann Vitodens 111-W F39 fault code mean?
The F39 fault code indicates a malfunction with the heating circuit sensor in the Viessmann Vitodens 111-W boiler. This sensor is crucial for monitoring the temperature of the heating circuit, and its failure can lead to inefficient heating or system shutdown.
Common Causes
- Faulty Sensor: The heating circuit sensor may be defective or damaged, leading to incorrect temperature readings.
- Wiring Issues: Damaged or loose wiring connections to the sensor can disrupt its functionality, resulting in the F39 fault code.
Can I fix it myself? (DIY)
It is recommended to call a Gas Safe Engineer for this issue, as it involves electrical components and potential gas safety risks. Attempting to fix it yourself could lead to further complications.
Estimated Repair Cost (2026 UK Prices)
The estimated repair cost for replacing the heating circuit sensor is around £150 to £250. This includes the cost of the part and labour, as sensor replacement typically requires professional expertise.