Brush bar does not spin on carpet but spins freely by hand when vacuum is off.

Safety first: Remove the battery before inspecting the floor head.

Steps to try:

• Test on hard floor: Try the vacuum on a hard surface. If the brush spins there but not on carpet, the drive is slipping under load.
• Inspect brush bar: Remove and check that the brush bar bearings are smooth. Replace the bar if stiff or worn.
• Check drive components: If accessible, inspect the belt or gear for wear or glazing. A stretched belt will slip under load.
• Replace floor head: On many Gtech models, the drive components are not separately serviceable. Replace the motorised floor head if the brush still fails to turn on carpet.