What does the Viessmann Vitodens 222-F F23 fault code mean?
The F23 fault code on the Viessmann Vitodens 222-F indicates a flame failure, meaning the boiler has not detected a flame when it attempted to ignite. This can lead to the boiler shutting down to prevent unsafe operation.
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 not 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. However, you can check the gas supply and ensure the boiler pressure is within the normal range (usually between 1-1.5 bar) and reset the boiler if necessary.
Estimated Repair Cost (2026 UK Prices)
Repair costs for the F23 fault can range from £100 to £300, depending on whether the issue is a simple gas supply blockage or requires replacement of the flame sensor, which typically costs around £150.