Symptoms
- Disposal hums when switched on
- No grinding sound
- Water sits in the sink
- Sound stops if you hold the switch, then starts again
Likely causes
- CommonObject jamming the flywheelA utensil, bone, or fruit pit is wedged between the flywheel and grind ring.
- CommonFlywheel seized from disuse or rustDisposals left idle for weeks can seize slightly, especially in humid areas.
- PossibleWorn motor bearingsOlder units can hum without turning even when clear.
- Less commonCapacitor or motor winding failureThe motor tries to start but can't develop torque.
What to do
- Turn off the wall switch and unplug or cut power at the breaker before reaching in.
- Shine a flashlight down the drain to look for a visible object.
- Insert a 1/4-inch hex wrench into the bottom center hole of the disposal (most models have one) and turn it back and forth to free the flywheel.
- If there's no hex hole, use a broom handle wedged against a disposal blade from the top to rock it free.
- Remove any object you find with tongs or pliers, never your hand.
- Restore power and press the small red reset button on the bottom of the unit.
- Turn on cold water, then switch the disposal on to test.
Tools and parts
- 1/4-inch hex wrench (often included with the disposal)
- Flashlight
- Tongs or pliers
Garbage disposal hex wrenchSearch: “disposal offset wrench replacement”
When to call a pro
If the flywheel turns freely by hand but the motor still just hums with power on, the motor itself has likely failed and the unit needs replacing.
Safety
Use caution
Always cut power before putting anything into the disposal; the switch alone can be flipped by someone else.