SO claims complete innocence but I know he did something. I could hear the racket all the way across the house. He was using the power head on the hardwood and literally could not hear me yelling to turn it off. When he finally shuts it off the vac motor stopped but began to run very slowly! I unplugged it, plugged it back in and all was well (not). This unit has it's controls on the wand handle. Nothing happens when it's plugged back in and wand controls act normally. Off, vac on, vac and power head on. But if you shut it off it does the low speed trick until it's unplugged. WTF?