A garbage disposal that hums but does not spin usually has a jammed impeller plate or a motor receiving power but unable to start. Do not leave it humming because the motor can overheat; disconnect power before attempting to clear a jam.
Turn it off immediately if it only hums
Leaving a stalled motor energized builds heat and may trip its thermal protection. Turn off the switch and disconnect the circuit or plug as appropriate before any attempt to free the jam.
Never put your hand inside the disposal
Even with power off, broken glass, metal, or sharp objects may be inside. Use tongs for visible objects and the manufacturer’s turning wrench or access point to move the mechanism from the intended location.
Free the jam and confirm the mechanism turns freely
Work the appropriate tool gently in both directions until resistance clears. Remove the object that caused the jam and verify nothing loose remains before restoring power.
Reset overload protection only after the cause is removed
Some models have an underside reset button after the motor cools. If it jams again, hums with no obstruction, or trips protection repeatedly, leave the disposal out of service and arrange repair or replacement.
Sources
- U.S. Consumer Product Safety Commission — Electrical Safety — Household electrical hazards and safe response to overheating, outlets, switches, and breakers.