Garbage Disposal Hums But Doesn’t Work — What It Means & How to Fix It

If your garbage disposal makes a humming noise when you flip the switch but the blades don’t spin, you’re probably worried it’s dead. Here’s the good news: this is usually a jammed flywheel, not a burned-out motor, and you can fix it in about 2 minutes.

This guide explains exactly why your disposal hums, how to fix it yourself, and when a humming disposal actually does mean replacement time.

Good News: This Usually Isn’t a Dead Motor

The humming sound tells you something important: your motor is getting power and trying to run. If the motor were dead, you’d hear nothing at all.

What’s actually happening:

The motor is energized
It’s trying to spin the flywheel (the grinding plate)
Something is blocking the flywheel from turning
The hum is the motor straining against the obstruction

This is the most common garbage disposal problem — and one of the easiest to fix. About 9 out of 10 humming disposals just need the jam cleared.

Understanding how a disposal works helps here: inside the unit, an electric motor spins a flat plate (the flywheel) at high speed. Metal “impellers” on the plate fling food against a grind ring, breaking it into tiny pieces that wash down the drain. When something gets wedged between the impellers and the grind ring, the flywheel can’t turn — but the motor keeps trying.

The 2-Minute Fix

Here’s the quick version:

Turn off the wall switch and unplug the disposal (or turn off the breaker)
Find the hex hole on the bottom of the disposal
Insert a 1/4” Allen wrench into the hole
Rotate back and forth until the flywheel moves freely
Remove the obstruction with pliers (never your hand)
Press the reset button (red, on the bottom)
Restore power, turn on cold water, and test

That’s it. For the detailed version with photos, see our jammed disposal fix guide.

Need help with the reset button? See our reset guide.

Step-by-Step: Freeing a Jammed Flywheel

Let’s break down each step in more detail so you can do this confidently.

Step 1: Kill the Power Completely

This is critical for safety. A jammed disposal can suddenly free itself when you’re working on it.

Turn off the wall switch
Unplug the disposal under the sink, OR
Turn off the circuit breaker labeled “disposal” or “kitchen”

Don’t skip the breaker/unplug step. The wall switch alone isn’t enough — it could be wired incorrectly, or someone could flip it while you’re working.

Step 2: Locate the Hex Socket

Look at the bottom center of your disposal. You should see a small hex-shaped hole (about 1/4” or 6mm). This is the manual rotation socket designed for exactly this situation.

Can’t find it? Some older or cheaper models don’t have this socket. If yours doesn’t, you’ll need to use the “broom handle method” described below.

Step 3: Insert the Allen Wrench

You need a 1/4” (6mm) Allen wrench. This is often called a “hex key” or “Allen key.”

Where to get one:

Most disposals come with a wrench taped to the side — check around the unit
Hardware stores sell them for $2-5
Many multi-tool sets include this size
InSinkErator sells a universal “Jam-Buster” wrench

Insert the wrench into the hex socket until it seats firmly.

Step 4: Work the Flywheel Loose

With the wrench in place, rotate it back and forth like you’re working a stubborn jar lid:

Push clockwise, feel resistance
Push counter-clockwise, feel resistance
Repeat, increasing range of motion each time

Initially the wrench might barely move. Keep working it. After a few back-and-forth motions, you should feel the flywheel break free and start moving more easily.

Goal: The wrench should rotate freely 360° in both directions with no resistance.

Step 5: Remove the Obstruction

Once the flywheel is free, the obstruction should be loose. Shine a flashlight into the disposal and identify what was causing the jam.

Use long-handled pliers or tongs to remove debris. Never put your hand inside a garbage disposal, even when the power is off.

Common items you’ll find:

Bone fragments
Fruit pits
Bits of glass
Utensils
Twist ties
Rubber bands

Step 6: Press the Reset Button

The reset button is a small red or black button on the bottom of the disposal. Overloading from the jam probably tripped this internal breaker.

Press firmly until it clicks. If it immediately pops back out, the flywheel might still be jammed — go back to step 4.

Step 7: Test

Restore power, turn on cold water, and flip the switch. The disposal should run normally.

If it still hums, repeat the process — sometimes multiple obstructions are present.

Alternative Method: No Hex Socket

If your disposal doesn’t have a hex socket on the bottom, you can still free the jam:

Turn off all power (switch, unplug, AND breaker)
Insert a wooden broom handle or thick dowel into the disposal from above
Press the handle against one of the impeller blades
Push/pull to rotate the flywheel back and forth
Remove obstruction and test

This method works but requires more force and is less precise than the wrench method.

Why It Hums But Won’t Spin

Inside your disposal, a spinning plate called the flywheel has metal “teeth” (impellers) that grind food against a stationary ring. When something gets wedged in there, the flywheel can’t turn.

Common obstructions:

Bones (chicken, fish, rib bones)
Fruit pits (peach, avocado, cherry)
Silverware that fell in
Glass shards
Bottle caps
Hard vegetable stems
Corn cobs
Seafood shells

The motor doesn’t know the difference between “jammed” and “working hard” — it just keeps trying to spin, creating that humming sound.

Important: Don’t let the disposal hum for more than 10-15 seconds. Extended humming can overheat and damage the motor. Turn it off and fix the jam.

Preventing Future Jams

Once you’ve cleared the jam, follow these practices to prevent recurrence:

Always run cold water — Run water for 15 seconds before and after grinding. Cold water solidifies grease so it gets chopped up rather than coating the blades.

Feed slowly — Don’t dump a pile of scraps in at once. Feed gradually while the disposal runs.

Know what to avoid:

Bones larger than chicken wing bones
Fruit pits
Corn husks and cobs
Celery strings
Artichoke leaves
Coffee grounds (build up over time)
Grease and oil
Pasta and rice (expand with water)

Monthly maintenance: Drop a few ice cubes and a splash of dish soap into the running disposal. This cleans the impellers and grind ring.

When the Motor IS Burned Out

Sometimes the motor really is the problem. Here’s how to tell:

Signs of a burned-out motor:

Burning or electrical smell — This is the clearest sign. If you smell burning, the motor windings are damaged.
Was humming, now completely silent — The motor overheated and failed.
Reset button won’t stay pressed in — Even after you’ve cleared any visible jam.
Disposal hummed for a long time — Extended humming without the flywheel moving causes motor damage.
Unit is old — Disposals over 8-10 years old with recurring problems may be at end of life.

If you see these signs, the motor can’t be repaired economically. You’ll need a new disposal.

Replacement cost:

New disposal: $80-300 depending on power and features
Professional installation: $150-200
DIY installation: Free if you’re comfortable (YouTube has good guides)

Silver lining: Modern disposals are quieter and more powerful than older models. A replacement might be an upgrade.

For a full diagnosis, see our complete troubleshooting guide.

Safety Reminders

When working on any garbage disposal:

Never put your hand inside — Even when power is off, the blades are sharp and the flywheel could release suddenly
Disconnect power completely — Wall switch plus unplug or breaker
Use tools, not fingers — Pliers, tongs, flashlight
Don’t use chemical drain cleaners — They can damage disposal seals and splash back
Keep face clear — Objects can be flung out when the disposal restarts

FAQ

Why does my garbage disposal hum but not work?

The motor is getting power, but the flywheel (spinning plate) is jammed against an obstruction. The hum is the motor trying to spin. Use a 1/4” Allen wrench in the bottom to free it.

Is a humming garbage disposal dangerous?

Not immediately, but don’t let it hum for more than 10-15 seconds. Extended humming can overheat and permanently damage the motor. Turn it off, clear the jam, then try again.

How do I know if the motor is burned out?

Signs include a burning smell, the reset button won’t stay pressed (even after clearing jams), or the disposal went from humming to completely silent. These indicate motor failure requiring replacement.

Can I fix a humming disposal myself?

Yes — most humming disposals just need the jam cleared. Insert a 1/4” Allen wrench into the bottom of the disposal and rotate back and forth. It takes about 2 minutes and no special skills.

What if my disposal doesn’t have a hex hole?

Use a wooden broom handle or thick dowel from above. Insert it into the disposal, press against an impeller blade, and work the flywheel back and forth until it breaks free. Remember to disconnect all power first.

Why does my disposal keep jamming?

Frequent jams usually mean you’re putting inappropriate items down the disposal (bones, pits, fibrous vegetables) or feeding too much at once. Run plenty of cold water and feed gradually.