My power head was not working and I took it in to see what was not working.
The fellow who attended me, realized I was using the wrong head for my carpet and explained what each head was for.
He also diagnosed that the power head was not the culprit, but the shaft with the electrical line. So I had a much cheaper repair--and on the first trip there!
The people there are so friendly with everybody and qive quick acknowledgement to each one who enters the store. It makes me feel right at home there.