What does the Worcester Bosch Greenstar Si F42 fault code mean?
The F42 fault code indicates a problem with the hot water sensor in the Worcester Bosch Greenstar Si boiler. This sensor is responsible for monitoring the temperature of the water, and a fault can lead to issues with hot water delivery.
Common Causes
- Faulty Hot Water Sensor: The sensor may be malfunctioning or damaged, leading to incorrect 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 to diagnose and repair this issue, as it involves electrical components and safety risks associated with gas appliances.
Estimated Repair Cost (2026 UK Prices)
The estimated repair cost for replacing the hot water sensor is around £150-£200, which includes parts and labour. This cost reflects the need for a qualified technician to ensure safe and proper installation.