A: There is a belt that attaches from your roller to the shaft of the motor on your powerhead. Usually if it is a flat belt it needs to be changed on a regular basis. Approximately every 3-6 months. It can though go in a day if you catch the corner of a throw rug, or maybe pick up a sock under the bed. If you have the belt on longer than 6 months what happens is that the roller will run slower due to the fact the belt is stretching. It may be spinning when you flip it over, but when it hits the carpet it is running at only half speed. If you have dirt plugged in the elbow of the powerhead it will also restrict the dirt from being sucked into the vaccum and will just shoot it back out again.
Replacing your belt often and cleaning the hair and debris out of the rollers will add to the life span of your power head
A: This probably occurred after something was caught in the roller of your power head and the roller has melted the belt. It will need to be replaced. Follow your manufactures directions in replacing or bring it into your nearest vacuum store.
A: As a store that also services machines we have found there is a lot more maintenance in keeping up a bagless over a bagged vacuum. With a bagless vacuum you do have to commit to empting and cleaning out the container and the filter after every use. Odors generally linger on the filter of bagless vacuums quicker than a bagged model Bagless untis generally need to have there filters changed every 6-12 months depending on use of course.
With a bagged vacuum you are throwing away the bag and the dirt after numerous uses and usually have to change the filter every 12 - 18 months. So in the end they are a lot less maintenance.