Short answer
If the disposal hums but doesn't spin, it's jammed: cut the power and turn the flywheel with the hex key in the socket underneath. If it's completely silent, press the red reset button on the bottom and check the breaker. If it's leaking, the location tells you whether it's a loose connection or a failed unit.
Match the symptom
It hums but doesn't turn
The motor is getting power, but the plate inside can't spin. Something is wedged between the plate and the grinding ring.
- Turn it off at the switch and unplug it or switch off the breaker. A humming motor can overheat if left on.
- Find the hex socket in the center of the bottom of the unit, under the sink.
- Insert the hex key (an Allen wrench, often 1/4 inch, that came with the disposal and is sometimes stuck to the side of it) and work it back and forth until it turns a full circle freely.
- Remove whatever caused the jam with tongs or pliers from the top, using a flashlight.
- Press the reset button, restore power, and run it with cold water.
No hex socket? Some older models have none. A wooden spoon handle pushed against the plate from above (power off) can free it.
It's completely silent
- Press the reset button. It's a small red button on the bottom of the unit. It pops out when the motor overheats or overloads. Wait a few minutes for it to cool first if it's just tripped.
- Check the breaker in your panel, and reset it if tripped.
- Check the plug under the sink, if it plugs into an outlet. Try another device in that outlet.
- Check the wall switch. Some kitchens have a switch that can fail.
If it's still silent after all four checks, the motor or wiring has failed. That's a replacement or electrical job.
It runs but the sink drains slowly
- Disposal isn't grinding fully: run more cold water, feed it smaller amounts.
- Clog in the trap or drain line after the disposal. See clogged drain.
- Dishwasher backing into the sink points to the same shared drain clog.
It makes grinding or rattling noises
Turn it off. Something hard, like a fruit pit, bottle cap, silverware or glass, is inside. Remove it with tongs (power off). A rattle that continues when empty can mean a loose mounting or worn internal parts.
It smells bad
Food debris builds up under the splash guard and on the grinding chamber.
- Scrub the underside of the rubber splash guard with a brush and dish soap.
- Grind a few ice cubes, then some citrus peel, with cold water running.
- Keep running water for several seconds after grinding to flush the line.
If it's leaking, find out where
Dry the unit with a towel, put a dry paper towel underneath, and run water. Look closely.
- From the top, where it meets the sink: the sink flange's plumber's putty or mounting has failed, or the mount has loosened. Often repairable by tightening or resealing the flange.
- From the side connections: the dishwasher hose inlet or the discharge pipe to the drain. Tightening the clamp or slip nut, or replacing a gasket, usually fixes it.
- From the bottom of the unit: water is coming from inside the disposal body, which means the internal seals have failed or the housing is cracked. This can't be repaired. The disposal needs replacing.
What not to put in a disposal
- Grease, oil and fat
- Fibrous food: celery, corn husks, onion skins, artichokes
- Starchy food that swells: pasta, rice, potato peels in quantity
- Coffee grounds and eggshells, which build up sludge in the drain line
- Bones and fruit pits
- Anything that isn't food
What not to do
- Don't keep flipping the switch while it hums. You'll burn out the motor.
- Don't reach in with your hand.
- Don't pour chemical drain cleaner into a disposal. It can damage the unit and splash back.
- Don't run it with hot water to clear grease. Cold water keeps grease solid so it gets ground and flushed rather than coating the pipes.
Repair or replace?
Worth fixing yourself: jams, tripped reset buttons, loose connections, a clog in the trap, smells.
Time to replace: leaks from the bottom of the unit, a motor that won't run after reset and breaker checks, frequent jams despite careful use, or rust and corrosion on the housing. Replacing a disposal involves plumbing and electrical connections. Many homeowners hand it to a plumber, especially when the wiring is hardwired rather than plugged in.
What to tell the plumber
- Symptom: humming, silent, leaking, noisy, or slow draining
- Where any leak appears
- What you've tried (hex key, reset, breaker)
- The make and approximate age if known
See garbage disposal repair for how plumbers handle repairs and replacements.
Frequently asked questions
Why is my garbage disposal humming but not working?
It's jammed. Turn off the power, then use the hex key in the socket on the bottom of the unit to turn the plate back and forth until it spins freely. Remove the object with tongs, press reset and try again.
Where is the reset button on a garbage disposal?
On most units it's a small red button on the bottom of the disposal, under the sink. If it has popped out, press it in firmly after letting the motor cool.
Can a leaking garbage disposal be repaired?
It depends where it leaks. Leaks at the sink flange or the side connections can usually be fixed. Leaks from the bottom of the unit mean internal failure, and the disposal needs replacing.
Should I use hot or cold water with a garbage disposal?
Cold. It keeps grease solid so it's ground up and flushed through, instead of melting and coating the drain further down.
Can I put coffee grounds down the disposal?
It's best not to. Coffee grounds don't jam the disposal, but they collect as sludge in the drain line and contribute to clogs.