What does the Viessmann Vitodens 111-W F68 fault code mean?
The F68 fault code on the Viessmann Vitodens 111-W indicates a problem with the domestic hot water (DHW) temperature differential. This typically means that the temperature difference between the flow and return of the DHW circuit is outside the expected range, which can affect the efficiency and performance of the boiler.
Common Causes
- Faulty DHW Sensor: A malfunctioning temperature sensor may provide incorrect readings, leading to the F68 fault code.
- Blocked Heat Exchanger: A blockage in the heat exchanger can restrict water flow, causing an abnormal temperature differential.
Can I fix it myself? (DIY)
It is recommended to call a Gas Safe Engineer for this issue, as it involves gas and electrical components that require professional expertise. Attempting DIY repairs could be dangerous.
Estimated Repair Cost (2026 UK Prices)
The estimated repair cost for resolving the F68 fault could be around £150 to £300, depending on whether the DHW sensor needs replacement or if the heat exchanger requires cleaning. This cost reflects the complexity of the repairs and the need for professional service.