What does the Worcester Bosch Greenstar i F39 fault code mean?
The F39 fault code indicates a problem with the flame sensor in the Worcester Bosch Greenstar i boiler. This sensor is responsible for detecting the presence of a flame; if it fails, the boiler will not operate safely.
Common Causes
- Dirty Flame Sensor: A buildup of soot or debris can prevent the sensor from accurately detecting the flame.
- Faulty Flame Sensor: The sensor itself may be malfunctioning or damaged, requiring replacement.
Can I fix it myself? (DIY)
While cleaning the flame sensor can be a DIY task, it is highly recommended to call a Gas Safe Engineer for any gas or electrical issues to ensure safety and compliance with regulations.
Estimated Repair Cost (2026 UK Prices)
The estimated cost for replacing a faulty flame sensor in a Worcester Bosch Greenstar i boiler is around £120. This includes the cost of the part and labour, reflecting the typical pricing for professional repairs in the UK.