What does the Worcester Bosch Greenstar i F90 fault code mean?
The F90 fault code on the Worcester Bosch Greenstar i indicates a faulty system alert, which typically suggests that the boiler has detected an issue that could affect its operation or safety. This may involve problems with the system pressure, electrical components, or sensor malfunctions.
Common Causes
- Low System Pressure: If the pressure in the heating system drops below the required level, it can trigger the F90 fault code.
- Electrical Faults: Issues with wiring, connections, or components such as sensors can lead to system alerts and the F90 code being displayed.
Can I fix it myself? (DIY)
Before attempting any repairs, check the system pressure on the gauge; if it’s low, you can safely re-pressurise the system by following the manufacturer’s instructions. However, for electrical issues or if you’re unsure, it’s crucial to call a Gas Safe Engineer to avoid safety risks.
Estimated Repair Cost (2026 UK Prices)
The estimated repair cost for resolving an F90 fault could range from £100 to £300, depending on whether the issue is simply a pressure adjustment or requires replacement of electrical components or sensors.