How to fix Viessmann Vitodens 100-W fault code F56

What does the Viessmann Vitodens 100-W F56 fault code mean?

The F56 fault code on the Viessmann Vitodens 100-W indicates a malfunction with the heating circuit sensor. This sensor is crucial for monitoring the temperature of the heating system, and its failure can lead to improper heating operation.

Common Causes

  • Faulty Sensor: The heating circuit sensor may be defective or damaged, leading to inaccurate temperature readings.
  • Wiring Issues: Damaged or loose wiring connections to the sensor can disrupt its functionality, causing the fault code to appear.

Can I fix it myself? (DIY)

It is recommended to call a Gas Safe Engineer for this issue, as it involves electrical components and potentially gas-related systems. Attempting to fix it yourself could be dangerous.

Estimated Repair Cost (2026 UK Prices)

The estimated repair cost for replacing a faulty heating circuit sensor on a Viessmann Vitodens 100-W is approximately £150 to £200. This includes the cost of the part and labour, as sensor replacements typically require professional installation.