How to fix Viessmann Vitodens 050-W fault code E305

What does the Viessmann Vitodens 050-W E305 fault code mean?

The E305 fault code indicates a problem with the ignition electrode in the Viessmann Vitodens 050-W boiler. This typically means that the electrode is either faulty or not functioning properly, preventing the boiler from igniting.

Common Causes

  • Faulty Ignition Electrode: The electrode may be damaged or worn out, leading to failure in generating the necessary spark for ignition.
  • Dirty Electrode: Accumulation of soot or debris on the electrode can hinder its ability to create a spark, resulting in ignition failure.

Can I fix it myself? (DIY)

It is recommended to call a Gas Safe Engineer for this issue, as working with gas appliances can be dangerous. Attempting to fix ignition-related problems without proper training may lead to safety hazards.

Estimated Repair Cost (2026 UK Prices)

The estimated repair cost for replacing the ignition electrode is around £150 to £200. This includes the cost of the part and labour, as ignition electrodes are relatively inexpensive, but professional installation is essential for safety.