Garbage Disposal Not Working? Humming, Silent or Jammed: How to Fix It
A disposal that hums is jammed; one that is silent has tripped its reset or lost power. How to tell which, clear it safely and know when it is worn out.
If the disposal hums but does not spin, something is jamming the grinding plate: turn off the power and free it with a hex wrench from underneath. If it makes no sound at all, press the red reset button on the bottom of the unit, then check the switch, plug and breaker.
- Difficulty
- Easy
- Time
- 10–30 minutes
- Typical cost
- $0 to fix a jam or reset; a replacement disposal costs considerably more
On this page · 9 sections
Before you start
- 1/4-inch hex (Allen) wrench or the wrench supplied with the disposal
- Flashlight
- Long tongs or pliers (never your hand)
- Bucket and towel
- Non-contact voltage tester (optional)
A garbage disposal that stops working usually tells you what is wrong by the sound it makes, or does not make, when you flip the switch. Most failures are a jam or a tripped overload protector, and both can be fixed in a few minutes with the power off and a simple hex wrench. Safety comes first: a disposal is a motor with grinding parts, so your hands never go into the opening.
How a disposal works
Food goes through the sink opening onto a spinning plate with two small hinged lugs called impellers. They throw food against a stationary grind ring around the edge, which breaks it into small particles that wash down the drain. The motor below has a built-in overload protector. InSinkErator describes it as a device that turns the disposal off automatically if it is jammed, run for a very long time, or has another problem.
Diagnose by sound
| What happens at the switch | Likely cause | Go to |
|---|---|---|
| Hums but does not spin | Jammed grinding plate | Fix 2 |
| Completely silent | Tripped reset, switch, plug or breaker | Fix 1 |
| Runs, then stops after a few seconds | Overheating or a partial jam | Fix 2, then Fix 1 |
| Spins, but water backs up in the sink | Clog in the drain line past the disposal | Fix 3 |
| Spins with a loud grinding or rattling | Hard object such as a utensil or bottle cap inside | Fix 2 |
| Water leaks under the sink | Loose connection or failing unit | When to call a pro |
Fix 1: Reset the overload protector
- Turn the disposal switch off.
- Look under the sink at the bottom of the disposal, facing the floor. Most units have a small red button there. InSinkErator notes that a tripped button sits about a quarter inch lower than normal.
- Press it gently. If it will not stay in, wait about ten minutes for the motor to cool and try again.
- Some newer models with a plug-in connection have an automatic overload instead of a button; the manufacturer advises turning the unit off (or unplugging an air-switch model) and letting it cool for up to 20 minutes.
- Turn on the cold water and then the switch.
If it is still silent, check that the disposal is plugged in (if it uses a plug), that the wall switch works, and that the breaker or GFCI outlet under the sink has not tripped.
Fix 2: Clear a jam
- Turn off the switch and unplug the unit or switch off its breaker. Never reach into a disposal, even with the power off.
- Insert a hex wrench into the socket in the center of the bottom of the unit.
- Work the wrench back and forth in both directions until it turns a full circle freely. This rotates the plate and frees whatever is wedged against the grind ring.
- With a flashlight, look into the sink opening and remove the object with tongs or pliers.
- Press the reset button, restore power, run cold water and test.
If your disposal does not have a hex socket underneath, some models can be turned from above with a short broom handle pushed against an impeller, with the power off.
Fix 3: Disposal runs but the sink drains slowly
When the motor spins normally but water stands in the sink, the clog is in the trap or drain line beyond the disposal. Turn off the power, put a bucket under the trap, and remove and clean the P-trap. Avoid chemical drain openers in a disposal; they can damage parts and make the next repair dangerous. If your home has a septic system, the EPA advises limiting disposal use altogether, because ground food adds fats, grease and solids that can clog the drainfield.
Keep it working
- Run cold water before, during and for several seconds after grinding.
- Feed food gradually rather than packing the chamber.
- Keep grease, oil, coffee grounds, eggshells in large amounts, fibrous peels and bones out of it.
- Never put glass, metal, plastic, or caustic chemicals into the disposal.
- Grinding a few ice cubes occasionally can help knock residue off the grind ring.
Common mistakes
- Reaching in with a hand. Use tongs, even with the power off.
- Pressing reset repeatedly on a jammed unit. Clear the jam first or the overload will keep tripping and the motor will overheat.
- Using hot water while grinding greasy food. Grease melts, then hardens further down the drain.
- Forcing the hex wrench with an extension. Firm pressure is fine; a cheater bar can break the socket.
When to call a pro
Call a plumber or electrician if the disposal leaks from its body, if the breaker trips again as soon as you reset it, if there is a burning smell, or if the motor hums even after the plate turns freely. Leaks from the unit’s housing usually mean the disposal has reached the end of its life and needs replacing. Wiring a hardwired disposal involves household electrical circuits, so hire a licensed electrician if you are not comfortable working on them.
Sources
- InSinkErator: Resetting a garbage disposal
- EPA: How to care for your septic system (garbage disposals and drains)
Spotted an error or an outdated step? Tell us and we will check it against the sources.