What does the Viessmann Vitodens 200-W F34 fault code mean?
The F34 fault code indicates a malfunction with the outdoor temperature sensor in the Viessmann Vitodens 200-W boiler. This sensor is crucial for the boiler’s ability to adjust its operation based on external temperature conditions.
Common Causes
- Wiring Issues: Damaged or loose wiring connections to the outdoor temperature sensor can lead to incorrect readings or complete sensor failure.
- Sensor Failure: The outdoor temperature sensor itself may be faulty due to wear and tear or exposure to harsh weather conditions, resulting in inaccurate temperature measurements.
Can I fix it myself? (DIY)
It is recommended to call a Gas Safe Engineer for this issue, as working with boiler components can be dangerous and requires professional expertise to ensure safety and compliance with regulations.
Estimated Repair Cost (2026 UK Prices)
The estimated repair cost for replacing the outdoor temperature sensor is around £150 to £250, which includes the cost of the part and labour. This estimate reflects the typical price for parts and professional service in the UK.