What does the Viessmann Vitodens 050-W E357 fault code mean?
The E357 fault code on the Viessmann Vitodens 050-W indicates a malfunction in the system mixing valve, which is responsible for regulating the temperature of the water circulating through the heating system. This issue can lead to inadequate heating or hot water supply, affecting overall system performance.
Common Causes
- Faulty Mixing Valve: The mixing valve may be stuck or malfunctioning, preventing it from properly mixing hot and cold water.
- Electrical Issues: There could be a problem with the electrical connections or control signals to the mixing valve, leading to its failure to operate correctly.
Can I fix it myself? (DIY)
It is recommended to call a Gas Safe Engineer for this issue, as it involves gas and electrical components that require professional handling for safety and compliance with regulations.
Estimated Repair Cost (2026 UK Prices)
The estimated repair cost for replacing the mixing valve on a Viessmann Vitodens 050-W is approximately £350. This includes the cost of the part and labour, reflecting the complexity of the repair and the need for a qualified technician.