If you have tried a hard surface, dampened your feet, replaced the batteries with fresh ones, and performed a reset, but the persists, the unit likely has a manufacturing defect in the BIA circuit.
The "Error 7" message on a new Tanita scale—specifically modern Bluetooth-enabled (BLE) models like the —typically indicates a Bluetooth communication failure between the scale and your mobile device. JustAnswer Troubleshooting Steps for Error 7 tanita scale error 7 new
Yes, for connected models (Bluetooth/Wi-Fi). Some early BC-1000 and RD-545 units had overly sensitive motion sensors, patched via app updates. If you have tried a hard surface, dampened