What does the Viessmann Vitodens 050-W E291 fault code mean?
The E291 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.
- Mechanical Failure: The valve mechanism may have worn out or broken, leading to its inability to function as intended.
Can I fix it myself? (DIY)
It is recommended to call a Gas Safe Engineer to address this issue, as it involves gas and water systems that can be hazardous if not handled correctly. Attempting to fix it yourself may lead to further complications.
Estimated Repair Cost (2026 UK Prices)
The estimated repair cost for replacing the system drain valve is approximately £150 to £250. This includes the cost of the part and labour, as it requires professional installation to ensure safety and compliance with regulations.