You can fix this
Likely cause: a jam
Something is wedged in the grinding chamber, so the motor hums but cannot turn. Free it with a wrench and tongs, never your hand.
Why this happens
Family Handyman's plumbers say a humming disposal is most likely stuck, often on a piece of food or a utensil wedged in the impeller. Moen says the motor hums because it cannot turn the grinding mechanism, and that bones and fibrous scraps like husks can lodge inside smaller units. This Old House adds that spoons, coins and rings are frequent offenders. The good news: Family Handyman says a hum means power is reaching the unit, so you can rule out an electrical problem.
How to fix it
- Turn the wall switch off. Then, with dry hands, unplug the disposal under the sink, or turn its breaker off if it has no plug. If the outlet, the plug or the cord is wet, do not touch them. Use the breaker instead.
- Put on safety glasses. This Old House recommends them to protect your eyes from debris. Then shine a flashlight down the drain. If you can see what is stuck, lift it out with tongs or needle-nose pliers. Keep your hand out.
- Look at the very bottom of the disposal, dead center, for a hex-shaped hole. If there is one, fit the small wrench that came with the unit. InSinkErator says a standard 1/4-inch Allen wrench also works on its disposals.
- Work the wrench back and forth until it turns freely in full circles both ways. Then take the wrench out.
- No hole on the bottom? Some disposals are freed from above, with the power still off. Moen has you set its unjamming wrench on the turntable through the sink opening, and Waste King says a wooden spoon handle or an unjamming wrench works. Turn until the turntable rotates freely, then take the tool out.
- Look inside again with the flashlight and remove anything loose with tongs or pliers.
- Press the red reset button on the disposal until it stays in.
- Check that the wrench, tongs and anything else are out of the sink and that nobody is near the drain opening, as Moen advises. Then restore power, turn on the cold water and flip the switch. If it only hums, switch it off and cut the power again before you repeat the wrench step. InSinkErator says you may need to repeat it several times.
When to stop. If the wrench will not turn it at all, if it still only hums once it turns freely, or if you smell burning, stop and call a plumber.
If this does not fix it, tell the plumber
- The disposal hums but does not spin.
- Whether the wrench turned it freely, and what you pulled out.
- Whether the reset button stayed in afterward.
- The brand and model from the label on the unit.
Build the full list: what to tell the plumber.
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