Diagnosis
Friction burn. The drive belt for the motorized floorhead is slipping or the brush roll is obstructed, causing the belt to overheat against the motor pulley.
How to Fix It
Turn off and unplug the vacuum. Remove the floorhead by pressing the two release latches. Inspect the brush roll. Remove any wound hair, string, or debris. Check the belt for signs of melting, stretching, or wear. Replace the belt if damaged. Ensure the brush roll spins freely by hand.
If That Didn't Work
The burning smell may originate from the main motor if the primary filter is clogged. Perform a complete filter cleaning: empty the dust cup, rinse the foam filter, and tap out the felt filter. Let all parts dry for 24 hours before reassembly.
Heads Up
The belt and brush roll are consumable parts. Check them every 3-6 months for wear, especially if you have long-haired pets. A dragging brush roll will burn out belts quickly.