What does the Viessmann Vitodens 050-W E299 fault code mean?
The E299 fault code indicates a malfunction with the system supply sensor, which is responsible for monitoring the temperature of the water supplied to the heating system. This issue can lead to inefficient heating and may cause the boiler to shut down to prevent damage.
Common Causes
- Faulty Sensor: The supply sensor may be defective or damaged, causing inaccurate temperature readings.
- Wiring Issues: Damaged or loose wiring connections to the sensor can disrupt its functionality and lead to the fault code being triggered.
Can I fix it myself? (DIY)
It is recommended to call a Gas Safe Engineer to diagnose and repair this issue, as it involves electrical components and safety risks. Attempting to fix it yourself may void warranties or lead to further complications.
Estimated Repair Cost (2026 UK Prices)
The estimated repair cost for replacing the system supply sensor is around £150 to £200, which includes the cost of the part and labour. This price reflects the specific nature of the sensor and the expertise required for installation.