What does the Viessmann Vitodens 050-W E336 fault code mean?
The E336 fault code indicates a problem with the system drain valve, which may be stuck or malfunctioning, preventing proper drainage of the heating system. This can lead to pressure issues and affect the overall performance of the boiler.
Common Causes
- Blocked Drain Valve: Debris or sediment may be obstructing the valve, preventing it from opening or closing properly.
- Faulty Valve Mechanism: The internal components of the drain valve may be worn or damaged, leading to failure in operation.
Can I fix it myself? (DIY)
It is recommended to call a Gas Safe Engineer for this issue, as working with boiler components can be dangerous and requires professional expertise to ensure safety and compliance with regulations.
Estimated Repair Cost (2026 UK Prices)
The estimated repair cost for replacing the drain valve on a Viessmann Vitodens 050-W is approximately £150 to £250. This includes parts and labour, as the valve itself may cost around £50 to £100, with the remainder covering the engineer’s time and expertise.