HI, it's Jim from Crucial Vacuum!
First thing is to be sure to unplug your vacuum. Once you begin smelling a burning smell it's essential to stop vacuuming immediately.
One of two things may be happing here:
1) Your brush roll may need replacing. It's possible that the sides where it attaches to the vacuum have been worn down with age. The bristles falling off is a clear indicator that it's time to replace the brush roll. Also, look for debris, or hair that's wrapped around the brush. Remove all of this with either a razor, or a scissor.
2) Check your vacuums belt. Is it wrapped around the brush roll at all, or is too loose? If so, this means there's no tension around your brush roll and it could be causing your vacuum to overwork the motor and overheat, hence the smell.
Clean this area out and then replace the brush roll and belt. You should be seeing a noticeable difference in both your vacuums suction, and a lack in the burning smell.
You can purchase replacement parts for your vacuum direct from Crucial Vacuum with free shipping and an exclusive 10% coupon for Fixya.com readers, use code: FIXYA10
I hope this was helpful. If you would like further assistance, please feel free to give us a call at 877.750.9239. We have helpful and friendly customer care representatives on the line ready to assist you.
Crucial Vacuum Customer Care