What does the Viessmann Vitodens 100-W F70 fault code mean?
The F70 fault code on the Viessmann Vitodens 100-W indicates a faulty reset condition, which typically occurs when the boiler fails to restart after a fault or power interruption. This can prevent the boiler from operating normally and requires attention to restore functionality.
Common Causes
- Power Supply Issues: Intermittent power supply or electrical faults can prevent the boiler from resetting properly.
- Control Board Malfunction: A failure in the control board may lead to improper communication and reset failures.
Can I fix it myself? (DIY)
It is advisable to call a Gas Safe Engineer for this issue, as it may involve electrical components that require professional handling. Attempting to fix it yourself could pose safety risks.
Estimated Repair Cost (2026 UK Prices)
The estimated repair cost for addressing the F70 fault code could range around £150 to £300, primarily depending on whether the control board needs replacement or if electrical components require servicing.