What does the Viessmann Vitodens 111-W F37 fault code mean?
The F37 fault code on the Viessmann Vitodens 111-W indicates a problem with the flame sensor, which is responsible for detecting whether a flame is present during operation. If the sensor fails to detect the flame, the boiler will shut down to prevent unsafe conditions.
Common Causes
- Dirty Flame Sensor: A buildup of soot or debris on the flame sensor can prevent it from functioning correctly.
- Faulty Flame Sensor: The sensor itself may be defective or worn out, requiring replacement.
Can I fix it myself? (DIY)
It is recommended to call a Gas Safe Engineer for any repairs related to the flame sensor, as working with gas appliances can be dangerous. Attempting DIY repairs may void warranties and pose safety risks.
Estimated Repair Cost (2026 UK Prices)
The estimated cost to replace a faulty flame sensor on a Viessmann Vitodens 111-W is approximately £150 to £200, including parts and labour. This cost reflects the need for a qualified technician to ensure safe and proper installation.