What does the Vaillant ecoFIT pure F23 fault code mean?
The F23 fault code on a Vaillant ecoFIT pure boiler 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 gas from reaching the burner, causing a flame failure.
- Flame Sensor Issues: A faulty or dirty flame sensor may not detect the flame properly, leading to the boiler shutting down.
Can I fix it myself? (DIY)
It is recommended to call a Gas Safe Engineer for any gas-related issues, including flame failures. Attempting to fix gas appliances without proper qualifications can be dangerous.
Estimated Repair Cost (2026 UK Prices)
The estimated repair cost for addressing the F23 fault could be around £150 to £250, primarily for cleaning or replacing the flame sensor and ensuring proper gas supply, which are common issues associated with this fault.