Cordless SEBO vacuum will not start; red fault indicator flashes once repeatedly after power button is pressed.

Safety first: Switch the vacuum OFF and remove the battery pack before any disassembly. Never short battery terminals.

• Check battery seating: Remove the battery pack, inspect the contacts on both the battery and vacuum for bent pins, corrosion, or debris. Clean gently with a dry cloth and reseat firmly until it clicks.
• Test with a known-good battery: If available, insert a second SEBO cordless battery pack. If the unit powers on normally, the original battery is likely faulty.
• Inspect the power switch: With the battery removed, operate the power button repeatedly to feel for sticking or lack of tactile click. If the switch feels loose or jammed, the handle/switch assembly may need replacement.
• Visual check of wiring: If you are comfortable opening the housing, remove the screws on the handle or main body (per SEBO service manual), gently separate the halves, and inspect the wiring harness from the switch to the control PCB for broken, pinched, or burnt wires.
• Control board/fuse: Many SEBO cordless models have a small fuse or resettable protector on the main PCB. If visibly burnt or cracked, the board should be replaced as a unit rather than attempting component-level repair.
• When to stop: If the E1 fault persists after trying a known-good battery and verifying the switch and wiring, discontinue use and have the main control PCB and wiring harness tested and replaced by a SEBO service technician.