Garbage disposal humming but not spinning — San Francisco, California

When a garbage disposal hums but doesn't spin, the impeller is almost always jammed by a piece of food, bone, fruit pit, or stray utensil. The motor is still receiving power but can't turn the flywheel, and if you leave it humming for more than a few seconds it will trip the internal overload protector. First, turn it off at the wall switch. Most disposals have a hex socket on the bottom — insert a 1/4-inch Allen wrench and rock it back and forth to free the jam. Then press the red reset button on the underside. If it spins freely afterward and the obstruction is gone, you're done. If it still hums, the motor bearings may be seized or the start capacitor has failed — both usually mean replacement is more cost-effective than repair. A plumber will replace a standard 1/2 HP unit for $200–$450 including labor. Never put your hand inside the disposal, even when it's off.