What does the Viessmann Vitodens 200-W F23 fault code mean?
The F23 fault code on the Viessmann Vitodens 200-W indicates a flame failure, meaning the boiler is unable to detect a flame during operation. This can lead to the boiler shutting down to prevent unsafe conditions.
Common Causes
- Insufficient gas supply: A blockage or issue in the gas supply line can prevent the boiler from receiving the necessary gas to ignite.
- Faulty flame sensor: If the flame sensor is dirty or malfunctioning, it may fail to detect the flame, causing the boiler to shut down.
Can I fix it myself? (DIY)
It is recommended to call a Gas Safe Engineer for any gas or electrical issues, as working on these systems can be dangerous. However, you can check the gas supply and ensure that the boiler is properly reset according to the manufacturer’s instructions.
Estimated Repair Cost (2026 UK Prices)
The estimated repair cost for addressing the F23 fault could range from £150 to £300, depending on whether the issue is with the gas supply or requires replacement of the flame sensor, which typically costs around £100 to £200.