1. The height setting may be too low. You can adjust the setting using the dial on the base of the vacuum.
2. Check if the two pieces of cardboard that came as packaging material between the wheels have been removed.
If you still have some trouble pushing the vacuum, please take your vacuum to a technician. You can find your nearest BISSELL® Authorized Service Center by clicking http://www.bissell.com/support/product-support/service-centers or by calling 1-800-237-7691, available 24 hours a day.