What does the Viessmann Vitodens 050-W E374 fault code mean?
The E374 fault code indicates a low water cut-off issue in the heating system, which prevents the boiler from operating safely. This fault typically arises when the system detects insufficient water levels, potentially leading to overheating or damage.
Common Causes
- Low Water Pressure: Insufficient water pressure in the system can trigger the low water cut-off, causing the boiler to shut down.
- Faulty Pressure Sensor: A malfunctioning pressure sensor may incorrectly report low water levels, resulting in the E374 fault code.
Can I fix it myself? (DIY)
If you are comfortable with basic plumbing, you can check the pressure gauge on the boiler. If the pressure is below 1 bar, you can safely re-pressurise the system using the filling loop. However, for any gas or electrical issues, it is crucial to call a Gas Safe Engineer.
Estimated Repair Cost (2026 UK Prices)
The estimated repair cost for addressing the E374 fault could range from £150 to £250, primarily depending on whether the issue is a simple re-pressurisation or if a pressure sensor needs replacement, which can be more costly.