What does the Viessmann Vitodens 111-W F29 fault code mean?
The F29 fault code indicates that the flue gas temperature is too high, which can lead to overheating and potential damage to the boiler. This fault typically suggests an issue with the flue system or combustion process that needs to be addressed promptly.
Common Causes
- Blocked Flue: A blockage in the flue can restrict the flow of exhaust gases, causing them to overheat.
- Faulty Temperature Sensor: A malfunctioning temperature sensor may incorrectly report high temperatures, triggering the fault code.
Can I fix it myself? (DIY)
It is strongly advised to call a Gas Safe Engineer for this issue, as it involves gas and electrical components that can be dangerous if handled improperly.
Estimated Repair Cost (2026 UK Prices)
The estimated repair cost for addressing the F29 fault could range from £150 to £300, depending on whether the issue is a simple flue cleaning or requires replacement of the temperature sensor.