What does the Viessmann Vitodens 100-W E119 fault code mean?
The E119 fault code on the Viessmann Vitodens 100-W indicates low water pressure within the heating system. This can prevent the boiler from operating efficiently and may lead to further issues if not addressed promptly.
Common Causes
- Low Water Pressure: The system may have lost pressure due to leaks or insufficient water supply.
- Faulty Pressure Relief Valve: A malfunctioning valve can allow water to escape, leading to a drop in pressure.
Can I fix it myself? (DIY)
You can attempt to increase the water pressure by locating the filling loop and carefully adding water to the system until the pressure gauge reads between 1 and 1.5 bar. If the issue persists or if you suspect a leak, it is advisable to call a Gas Safe Engineer.
Estimated Repair Cost (2026 UK Prices)
The estimated repair cost for addressing low water pressure issues is around £150 to £250, depending on whether a leak needs to be fixed or if a component like the pressure relief valve requires replacement.