What does the Viessmann Vitodens 222-F F42 fault code mean?
The F42 fault code on the Viessmann Vitodens 222-F indicates a malfunction with the domestic hot water (DHW) sensor. This sensor is crucial for accurately measuring the temperature of the water, and a fault can lead to issues with hot water delivery.
Common Causes
- Faulty DHW Sensor: The 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 and cause the fault code to appear.
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 a faulty DHW sensor on a Viessmann Vitodens 222-F is approximately £150 to £200. This includes the cost of the part and labour, as the sensor itself typically costs around £50 to £100.