There could be several reasons why the brush on a vacuum cleaner is not spinning:
Power switch or button: First, check if the vacuum cleaner is turned on and the brush roll switch or button is engaged. Some vacuum models have a separate button or switch to activate the brush roll, and it may have accidentally been turned off.
Clogged brush or vacuum: If the brush roll is clogged with hair, threads, or debris, it may get stuck and not spin properly. Similarly, if the vacuum's suction pathway or air passages are blocked, it can cause the brush roll to stop spinning.
Worn-out belt: Vacuum cleaners typically have a belt that connects the motor to the brush roll. Over time, this belt can wear out, stretch, or break, preventing the brush roll from spinning. You may need to replace the belt if it's damaged.
Brush roll motor malfunction: The motor that drives the brush roll could be faulty or burned out, preventing it from spinning. This would require repair or replacement by a qualified technician.
Height adjustment setting: Some vacuum cleaners have a height adjustment feature that raises or lowers the brush roll depending on the type of flooring. If it's set too high for a particular carpet or surface, the brush may not make proper contact to spin.
Brush roll switch or wiring issue: There might be a problem with the electrical connection between the brush roll and the vacuum's motor, such as a loose wire or damaged switch.
Overheating protection: Some vacuum cleaners have safety mechanisms that shut off the brush roll when the motor gets too hot to prevent damage. If the vacuum is overheating, it may cause the brush roll to stop spinning until the motor cools down.
If you've checked the obvious issues like the power switch and clogs and the brush still isn't spinning, it's best to refer to your vacuum's user manual or contact the manufacturer's customer support for troubleshooting assistance. In some cases, it may be necessary to take the vacuum to a professional repair service for diagnosis and fixing.