DIAGNOSIS: The triple beep is a brush error. Hair or debris is tangled around the main roller, jamming it and triggering the sensor.
FIX: Power off the vacuum, flip it over, and remove the main brush cover. Cut and pull out all hair and threads wrapped around the roller ends and the axle. Reassemble and power on.
IF THAT DIDN'T WORK: The side brush might also be jammed. Remove it by unscrewing the center cap and check for obstructions. Also, ensure the main brush cover is clicked completely shut.
HEADS UP: Do this weekly if you have pets or long hair. Severe jams can burn out the brush motor. Consider upgrading to the anti-tangle brush designed for the G30 series.