How do I unjam and reset a garbage disposal?
Turn the switch off. If the disposal hums but does not spin, it is jammed: put the quarter-inch hex wrench in the socket on the bottom and work it back and forth until it turns freely. If it is completely silent, press the red reset button on the bottom. Then run cold water and try again. Never put your hand in the chamber.
A garbage disposal that stops working almost always falls into one of two categories, and you can tell which by listening.
It hums. The motor is getting power and trying to turn, but something is holding the plate. That is a jam.
It is silent. Nothing happens when you flip the switch. The built-in overload protector has tripped, which it does to protect the motor when it is jammed or overheated. That is a reset.
Both take about five minutes. Neither requires putting your hand inside the unit, and you should never do that even with the power off.
Before you start
- Turn the wall switch off. If the disposal is on a plug under the sink, unplug it. If it is hard-wired, turn off its breaker.
- Get a flashlight, a pair of tongs or needle-nose pliers, and a quarter-inch hex wrench. Most disposals come with one; look for it zip-tied to the unit or in the cabinet.
- Clear out from under the sink so you can see the bottom of the disposal.
If it hums: free the jam
- Find the hex-shaped socket in the center of the bottom of the disposal.
- Insert the hex wrench and work it back and forth. It will resist at first. Keep rocking it until it makes a full turn in both directions with no catch.
- Shine the flashlight down the drain opening. Use tongs to pull out whatever caused the jam: a bottle cap, a fruit pit, a piece of silverware, a bone.
- Press the reset button on the bottom of the unit. If the overload tripped while it was humming, the button will have popped out.
- Restore power, run cold water, and switch it on.
If your disposal has no hex socket, some models let you free the plate from the top with a wooden spoon handle. Power off, push the plate around from above, and never use your hand or a metal tool.
If it is silent: press reset
- With the switch off, feel along the bottom of the unit for a small square button. It is usually red. If it has tripped, it sits out from the housing.
- Press it in until it clicks and stays.
- Wait a few minutes if the unit was running hard before it stopped; the overload needs to cool.
- Restore power, run cold water, and switch it on.
If the button will not stay in, or pops again right away, the motor is drawing too much current. That is the end of the DIY road.
Run it right so it stays free
- Always run cold water before, during, and for a few seconds after grinding. Cold water keeps grease solid so it flushes through instead of coating the drain.
- Feed small amounts. A disposal is for scraps, not for the whole plate.
- Keep out fibrous and starchy things: celery, corn husks, onion skins, potato peels, rice, pasta, coffee grounds, and grease. They are the classic jam and clog makers.
- No chemical drain cleaners, ever. They ruin the seals and the pipes.
When it is time to replace it
Disposals are sealed units, and they are not economical to repair. Plan on a replacement when:
- water drips from the bottom of the housing, which means the internal seal has failed
- it trips the reset or the breaker repeatedly even when nothing is jammed
- it turns freely by hand but still only hums (a failed motor)
- it is around ten years old and has started grinding slower or louder
A replacement is a short visit, and while we are under the sink we check the trap, the dishwasher connection, and the supply lines, since a leak in any of those tends to show up at the same time.
Common questions
Where is the reset button?
On the bottom of the disposal, usually a small red or black square button, sometimes off to one side. Reach under the sink with a flashlight. It only pops out when the motor overload has tripped, so it should be flush most of the time.
What size wrench does a disposal take?
A quarter-inch hex (Allen) wrench. Most disposals ship with one, and it is often still zip-tied under the sink. Any quarter-inch Allen key works.
Can I use a chemical drain cleaner if the disposal drains slowly?
No. Drain chemicals damage the disposal's seals and the drain pipes, and they make the job dangerous for the plumber who opens the trap later. Slow draining is a trap or drain-line problem, not a disposal problem.
Related service: Faucet, Sinks, Disposals
These guides are for general information only. Plumbing work can involve water damage, electricity, gas, permits, and code requirements, and every home is different. If you are not sure, stop and call a licensed plumber. Do-it-yourself work is at your own risk. Read the full disclaimer.