Diagnosis
The burning smell emanating from your Bissell Pet Hair Eraser Turbo Rewind (Model 27909) is almost certainly the result of thermal friction. This occurs when the motorized brush roll becomes obstructed by tightly wound pet hair, long threads, or carpet fibers. When the brush roll cannot spin at its intended RPM, the drive belt—which is made of a synthetic rubber compound—continues to be driven by the motor pulley. This creates a "slipping" effect where the belt rubs violently against the pulley, generating intense heat and a distinct acrid, burning rubber odor. In some cases, the smell is caused by the motor itself overheating. If the vacuum's airflow is restricted due to a clogged filter or a blocked hose, the motor has to work harder to pull air, leading to internal heat buildup. However, if the smell intensifies specifically on carpet, it indicates that the resistance of the carpet pile is triggering the brush roll obstruction, confirming that the friction is happening at the floorhead level rather than the motor housing.
How to Fix It
To resolve the burning smell and prevent permanent motor damage, follow these precise steps to clear the drive system:
- Power down the unit completely and disconnect the power cord from the wall outlet to prevent accidental activation.
- Press the two release latches located on the sides of the floorhead to detach the vacuum head from the main canister body.
- Flip the floorhead over to expose the brush roll. Locate the brush roll guard or the end caps.
- Using a pair of heavy-duty scissors or a seam ripper, carefully cut through the hair and string wound around the brush roll. Do not pull the hair out by hand, as this can stretch the bristles or damage the belt. Cut along the length of the roll and then peel the debris away.
- Check the belt tension. If the belt looks "glazed" (shiny/melted) or has visible cracks, it has been compromised by the heat and must be replaced.
- Manually rotate the brush roll with your hand. It should spin smoothly with minimal resistance. If it feels "crunchy" or stuck, check the end bearings for trapped debris.
- Reattach the floorhead, ensure the connection is clicked firmly into place, and test the vacuum on a hard surface before moving back to the carpet.
If That Didn't Work
- Inspect the Pre-Motor Filter: A clogged filter reduces airflow, causing the motor to overheat and emit a burning plastic smell. Locate the filter, tap it firmly against a trash can to remove fine dust, or replace it if the fabric appears grey or blackened.
- Check for Hose Blockages: A partial clog in the suction hose creates backpressure. Remove the hose and drop a heavy coin or a small ball through it. If it doesn't pass through instantly, use a flexible plumbing snake or a wire hanger to clear the obstruction.
- Examine the Motor Pulley: If you replaced the belt but the smell persists, inspect the motor pulley for melted rubber residue from the previous belt. Use a small piece of fine-grit sandpaper to clean the pulley surface so the new belt can grip without slipping.
- Verify the Height Setting: If you are using the vacuum on very low-pile or thin carpets, the brush roll may be digging too deep into the fibers, creating excessive drag. Adjust the height setting to a higher position to reduce the load on the motor.
Heads Up
- Weekly Maintenance: Cut hair off the brush roll every two weeks regardless of whether you smell burning; once the belt starts slipping, it loses elasticity and will fail prematurely.
- Avoid "Wet" Carpets: Never use this vacuum on damp carpets. Moisture causes debris to clump and stick to the brush roll, increasing friction and the risk of belt burnout.
- Scent Warning: If the burning smell is accompanied by a visible spark or a loud grinding noise from the motor housing, stop using the unit immediately as this indicates a bearing failure in the motor.
- Belt Replacement: Only use genuine Bissell replacement belts. Generic rubber bands or non-spec belts will either snap instantly or slip, causing the burning smell to return.