What does the Viessmann Vitodens 100-W F81 fault code mean?
The F81 fault code indicates a faulty electrical supply to the boiler, which can prevent it from operating correctly. This issue may arise from problems in the power supply or internal electrical components.
Common Causes
- Power Supply Issues: A disruption in the electrical supply, such as a blown fuse or tripped circuit breaker, can lead to this fault code.
- Internal Component Failure: Faulty internal components, such as the control board or wiring, may also cause electrical supply problems.
Can I fix it myself? (DIY)
It is advisable to call a Gas Safe Engineer for this issue, as electrical faults can be complex and potentially dangerous. Attempting to fix electrical problems without proper training can lead to further damage or safety hazards.
Estimated Repair Cost (2026 UK Prices)
The estimated repair cost for resolving an F81 fault could range from £150 to £300, depending on whether the issue is a simple power supply fix or requires replacement of internal components like the control board.