DIAGNOSIS: The purifier is stuck in Wi-Fi pairing mode. This often happens after a failed or interrupted initial setup or if the unit lost connection and can't reconnect.
FIX: Force a restart to clear the Wi-Fi mode. Unplug the purifier from the wall outlet. Wait 60 seconds. While it's unplugged, press and hold the power button on the unit for 5 seconds. Plug it back in. The screen should show 'PWR' and the fan should be off, indicating a normal boot.
IF THAT DIDN'T WORK: Perform a full factory reset. With the unit unplugged, press and hold the power button AND the fan speed button simultaneously. While holding both, plug the unit back in. Continue holding the buttons for 5 seconds after plugging in. Release. The unit will reboot to factory defaults.
HEADS UP: After a reset, you will need to set up the purifier in the VeSync app again as if it were new. Your previous schedules and room size settings will be erased.