What does the Viessmann Vitodens 111-W F36 fault code mean?
The F36 fault code on the Viessmann Vitodens 111-W indicates a problem with the ignition transformer, which is responsible for generating the high voltage needed to ignite the gas burner. This fault can prevent the boiler from starting or cause it to shut down during operation.
Common Causes
- Faulty Ignition Transformer: The ignition transformer may have failed due to wear and tear or electrical issues, preventing it from producing the necessary voltage.
- Wiring Issues: Damaged or loose wiring connections to the ignition transformer can disrupt the electrical flow, leading to ignition failure.
Can I fix it myself? (DIY)
It is highly recommended to call a Gas Safe Engineer for this issue, as working with gas and electrical components can be dangerous. Attempting to fix the ignition transformer without proper training may lead to further complications or safety hazards.
Estimated Repair Cost (2026 UK Prices)
The estimated repair cost for replacing a faulty ignition transformer on a Viessmann Vitodens 111-W is approximately £250 to £350. This includes the cost of the part and labour, as ignition transformers can be expensive and require professional installation.