What does it mean if my Riello UPS display shows codes F09 or F10?
- MMaria RiceAug 29, 2025
If the Riello UPS display shows one or more of the following codes: F09, F10, it could indicate a UPS input stage malfunction. To resolve this, activate manual bypass (SWMB), switch off and re-start the UPS. Exclude manual bypass. Contact the nearest service centre if this problem persists. Alternatively, it could be due to Phase1 voltage being much lower than the other two phases (voltage imbalance). In this case, open the SWIN, switch on batteries, wait for sequence completion and close the SWIN.











