What does the Worcester Bosch Greenstar Ri F78 fault code mean?
The F78 fault code indicates a problem with the system’s efficiency, often related to issues with the heating system’s operation or components. This could lead to reduced performance and increased energy consumption.
Common Causes
- Blocked Heat Exchanger: A build-up of debris or limescale can restrict water flow, affecting efficiency.
- Faulty Sensors: Malfunctioning temperature or pressure sensors can provide incorrect readings, leading to inefficiencies.
Can I fix it myself? (DIY)
It is recommended to call a Gas Safe Engineer for this issue, as it may involve gas or electrical components that require professional handling for safety reasons.
Estimated Repair Cost (2026 UK Prices)
The estimated repair cost for addressing the F78 fault could be around £150 to £300, depending on whether a sensor replacement or heat exchanger cleaning is required. This estimate includes parts and labour.