Wondering what's going on in there?
How a garbage disposal works, in plain English
A garbage disposal works more like a cheese grater than a blender. There are no sharp blades inside.
Here's what happens when you flip the switch:
- The motor starts. It sits in the bottom half of the disposal and spins a metal plate very fast. Pros call it the flywheel.
- Blunt teeth fling the food outward. Two small metal lugs on the plate push food against the wall as it spins.
- A rough ring grates the food. The grater ring around the edge shreds food into tiny bits, like grating cheese.
- Water carries it away. Cold water washes the bits out a side pipe, through the U-shaped trap, and into the drain in the wall.
- The reset button protects the motor. If the motor gets too hot or gets stuck, the red button on the bottom pops out and cuts the power.
Most problems are one of three things: no power reaching it, something stuck between the plate and the ring, or a clog in the pipe after it. The questions at the top check them in that order.
Rather not do it yourself? Call a plumber.
That's a fine choice. Maybe you're busy. Maybe you're selling the house and just want it done right. A plumber can clear a clog, fix a leak or put in a new disposal.
Most plumbers charge $45–$200 an hour, and some add a fee to come out.
Find plumbers near you
Find plumbers near me →Opens Google Maps. We don't ask for your number.
What to say
Calling a pro? Here's what to say.
A few lines to read when they pick up, and the questions to ask before anyone comes out.
Before you call
Say this
Hi. My garbage disposal isn't working. When's the soonest you can get here? And what's your fee for the visit? Does it go toward the repair?
Always ask
- What's your fee to come out, and does it go toward the repair?
- Do you charge by the job or by the hour?
- Will you tell me the full price before you start any work?
Watch out if
- They push a full replacement on the first visit for a small problem.
- They won't give you a price before starting.
- They add an emergency fee without telling you first.
Feeling pushed to decide on the spot? You can say no and hang up. You owe nothing for a phone call.
Answer up to 5 quick questions. We'll give you the words a pro uses.
Answer the questions →More of a list person?
Common symptoms, causes, tests and costs
Find the row that sounds like your disposal. The quick test is something you can check yourself in a few minutes, with the power off.
| What you notice | What it probably is | Quick test | Do it yourself | With a pro | Verdict |
|---|---|---|---|---|---|
| Silent: no hum, no sound | The disposal isn't getting power | Check the plug, the outlet's reset button and the breaker | Free | Not needed | FIXSee the answer: The disposal isn't getting power |
| Silent, and the red button on the bottom sticks out | The reset button tripped | Press the red button on the bottom of the disposal | Free | Not needed | FIXSee the answer: The reset button tripped |
| Hums but doesn't spin | Something is jamming the spinning plate | Power off, then turn the hex key in the bottom center | $0–$10 | Not needed | FIXSee the answer: Something is jamming the spinning plate |
| Loud grinding or rattling | Something hard fell in | Power off, then look down the drain with a flashlight | Free | Not needed | FIXSee the answer: Something hard fell in |
| Disposal runs, but the sink won't drain | The drain below the disposal is clogged | Run water. Does it back up into the sink? | $0–$15 | $60–$150 | FIXSee the answer: The drain below the disposal is clogged |
| Water dripping from the disposal under the sink | The disposal is leaking | Dry it off, run a little water, and watch where drips start | Pro job | $50–$625 | CALLSee the answer: The disposal is leaking |
| Silent with the power on, or hums even when the plate turns freely | The disposal motor is worn out | Reset, power and hex key all check out, and it still won't run | Pro job | $200–$625 | CALLSee the answer: The disposal motor is worn out |
2026 U.S. averages, rounded. Pro prices include parts and labor. Most plumbers charge $45–$200 an hour, and some add a fee to come out. Nights, weekends and big cities cost more. See all repair prices
Want proof it's working?
The 30-second water test
Do this after any fix. No tools needed.
- Make sure nothing is in the drain. Look with a flashlight, never your hand.
- Run cold water at a medium stream.
- Flip the switch on and listen for 10 seconds.
- Turn the switch off and let the water run 15 more seconds.
- Smooth, steady whir, and water drains in a few seconds: it's working. A quick clunk right at start-up is normal.
- Hum, no spin: it's jammed or the motor is failing. Turn it off within 5 seconds.
- Grinding or rattling: something hard is inside. Switch off, unplug, and use tongs.
- Spins, but water backs up: the pipe below is clogged.
- Silent: no power is reaching it. Check the reset button, plug, outlet and breaker.
Not sure it's safe to keep using?
Turn it off right away if…
- You smell burning or see smoke. Turn off its breaker too.
- The breaker or outlet trips again after one reset.
- You see sparks, or the switch or outlet feels hot or buzzes.
- Water is leaking from the body of the disposal. Water and electricity don't mix.
- It hums for more than a few seconds without spinning. The motor can overheat.
And never put your hand in a disposal, even with the switch off. Unplug it first and use tongs.
Got a big repair quote?
Should you repair it or replace it?
The motor is sealed inside a disposal, so pros rarely fix a dead motor. They replace the whole disposal. Smaller problems, like a worn seal or a loose hose, are usually worth fixing.
- What failed? A seal or hose fix often runs $50–$125. A burned-out or seized motor almost always means a new disposal.
- How old is it? Disposals wear out. An older one that has started leaking from the bottom or humming without spinning is near the end.
- Is it under warranty? Many disposals come with a warranty of several years. Find the brand and model on the sticker on the side, then check the maker's website.
- The half rule. If a repair costs more than half the price of a new disposal installed, replacing usually makes more sense. Most people pay $200–$625 for a new one installed.
Example: a $90 seal fix on a disposal that still grinds well is worth it. A $350 motor repair is not, when a new disposal installed averages about $550.
Ran into a word you don't know?
Garbage disposal words, explained
Tap through these before you go looking. The drawings show roughly what each part looks like.
- Garbage disposal
- The grinder under your kitchen sink drain. It turns food scraps into tiny bits that wash down the pipe.
- Reset button
- A small red or black button on the bottom of the disposal. It pops out to cut the power when the motor gets too hot. Pros call it the overload protector.
- Hex key
- A small L-shaped wrench with six flat sides, also called an Allen wrench or disposal wrench. It fits the hole in the bottom center and turns the plate by hand.
- Spinning plate
- The round metal plate inside that the motor spins. Pros call it the flywheel or turntable.
- Blunt teeth
- Two small metal lugs on the spinning plate that push food outward. Pros call them impellers or lugs. They aren't sharp.
- Grater ring
- The rough metal ring around the inside wall. Food gets shredded against it. Pros call it the grind ring or shredder ring.
- Motor
- The electric part in the bottom half of the disposal that spins the plate. It's sealed inside the unit.
- Horsepower (HP)
- How strong the motor is, printed on the sticker on the side. Most home disposals are 1/3, 1/2 or 3/4 HP.
- Outlet reset button
- An outlet with TEST and RESET buttons that cuts power if it senses water or a fault. Pros call it a GFCI outlet. Press RESET to turn it back on.
- Breaker
- A safety switch in your home's breaker box (the gray metal panel). Turning off the disposal's breaker cuts its power.
- Wall switch
- The switch that turns the disposal on, usually on the wall near the sink. Some disposals use a button on the counter instead.
- Sink flange
- The metal ring in the bottom of the sink where the disposal hangs. A seal under it keeps water from leaking.
- Hose connections
- Where pipes and hoses join the side of the disposal, like the dishwasher hose and the drain pipe. A loose one can drip.
- Trap
- The U-shaped pipe under the sink. It holds a little water to block sewer smells, and it's where clogs often form. Pros call it the P-trap.
- Cup plunger
- A plunger with a flat rubber cup, made for sinks. The toilet kind has an extra flap on the bottom.
- Tongs
- Kitchen tongs or long pliers. Use them, never your hand, to pull things out of a disposal.
Still have questions?
Questions people ask most
Where is the reset button on a garbage disposal, and how long do I hold it?
The reset button is a small red button on the bottom of the disposal, under the sink. InSinkErator says a tripped button sits about a quarter inch lower. Turn the switch off, then press it gently until it clicks; you don't need to hold it. If it won't stay in, wait 10 minutes for the motor to cool and try again.
Can't find the reset button or the switch?
If you can't find the reset button, shine a flashlight on the very bottom of the disposal, facing the floor. The on switch is usually a wall switch near the sink. Some disposals use a button on the countertop instead, with a plug-in power box under the sink. Batch-feed disposals have no switch: you turn the stopper to start them.
Why does my garbage disposal hum but not work?
A garbage disposal that hums but won't work usually has something wedged inside, so the plate can't spin. Turn it off, unplug it, and turn the hex key in the bottom center to free it. If it turns freely and still hums, the motor is probably worn out.
Why won't my garbage disposal turn on at all?
A garbage disposal that won't turn on at all usually has a tripped reset button or no power. Check the red reset button on the bottom first. Then check the plug, the outlet's reset button and the breaker. If all of those are fine and it's still silent, the switch, wiring or motor may be bad. Call a pro.
Is a garbage disposal that's not working an emergency?
A garbage disposal that's not working is not an emergency, but smoke, a burning smell, sparks or a leak from its body is. Then turn off its breaker. Never put your hand inside, even with the switch off. Unplug it first and use tongs or pliers.
Will the dishwasher work if the garbage disposal doesn't?
A dishwasher can usually still run when the disposal is broken, but it may not drain if the disposal is clogged. Roto-Rooter says many dishwashers drain through the disposal, and food built up inside can block that drain. Clear any food out of the disposal first. A brand-new disposal also needs its knockout plug removed, Whirlpool says, or the dishwasher can't drain.
Can a garbage disposal run without water?
No, a garbage disposal shouldn't run without water. Whirlpool says cold water must flow into it the whole time it runs, and InSinkErator says to use a steady stream of cold water. The water carries the ground-up food down the drain.
Can I use drain cleaner in a garbage disposal?
No, don't use chemical drain cleaner in a garbage disposal. Chemical drain cleaner can harm the disposal's seals and metal parts. It can also splash on you if you plunge or open the pipe later. Use a cup plunger or clean the trap under the sink instead.
What shouldn't go down a garbage disposal?
Grease, bones, fruit pits, coffee grounds, eggshells, pasta, rice and stringy foods like celery shouldn't go down a garbage disposal. Never put in glass, metal or plastic. Run cold water before, during and after you use it.
How long do garbage disposals last?
Garbage disposals usually last 8 to 15 years, Bob Vila says. Is yours near the end of that range? If it hums without spinning, leaks from its body, or jams again and again, a new one is usually worth it.
How much does a new garbage disposal cost?
A new garbage disposal usually costs $200–$625 installed. The average is about $550, per HomeAdvisor. The disposal alone costs about $65–$425. Stronger ones cost more.
Who do I call for a garbage disposal that's not working?
Call a plumber to repair or replace a garbage disposal. If the outlet, the switch or the breaker for it keeps tripping or doesn't work, call an electrician instead.
How we built this
The questions follow the order a plumber checks a disposal: what it does at the switch, the reset button, the power, a jam, then the motor, the drain and leaks. Each answer makes some causes more likely and others less likely.
Prices are 2026 national averages from published repair-cost guides, rounded. Your local prices will differ.
- HomeAdvisor, garbage disposal replacement cost (June 2026)
- NerdWallet, how much it costs to replace a garbage disposal (April 2026)
- Bob Vila, garbage disposal repair cost (September 2023)
- InSinkErator, resetting a garbage disposal (read October 2026)
- InSinkErator, using cold water (read October 2026)
- Whirlpool, operating a batch-feed disposer (May 2026)
- Roto-Rooter, my dishwasher is not draining (read October 2026)
- Bob Vila, how long do garbage disposals last (August 2025)
- Fixr, garbage disposal repair cost (August 2025)
How we make money: some links go to parts stores that pay us a small commission, and some pro listings pay us when you call them. Verdicts come from the diagnosis, not from who pays more.