What does the Viessmann Vitodens 100-W F45 fault code mean?
The F45 fault code on the Viessmann Vitodens 100-W indicates a problem with the burner, which may prevent the boiler from igniting or operating efficiently. This issue can lead to heating and hot water supply interruptions.
Common Causes
- Faulty Ignition Electrode: A malfunctioning ignition electrode can fail to ignite the gas, leading to the F45 error.
- Gas Supply Issues: Insufficient gas pressure or blockages in the gas supply line can prevent the burner from receiving the necessary fuel.
Can I fix it myself? (DIY)
It is strongly advised to call a Gas Safe Engineer for any repairs related to gas or electrical components. Attempting to fix these issues without proper training can be dangerous.
Estimated Repair Cost (2026 UK Prices)
The estimated repair cost for the F45 fault could range from £150 to £300, depending on whether the ignition electrode needs replacement or if there are gas supply issues that require attention.