Garbage Disposal Humming But Not Working? How to Fix It

You flip the switch and hear a low hum. Nothing grinds and nothing spins and the sink stays full of water. A garbage disposal humming without working is one of the most common kitchen plumbing problems and it feels alarming the first time it happens. The good news is that the hum tells you something useful. The motor has power and it is trying to turn. Something is simply holding it back.

This guide explains why a garbage disposal hums but will not spin and how to fix it step by step. You will learn how to free a jammed garbage disposal with a hex key or a wooden spoon and how to use the garbage disposal reset button. You will also see what to check when the unit makes no sound at all and when the hum means the motor is finished and a replacement makes more sense than a repair.

Why a Garbage Disposal Hums but Does Not Spin

A garbage disposal does not have blades like a blender. Inside the grinding chamber sits a spinning metal plate called the flywheel. Two small metal pieces called impellers are attached to it. When the motor runs the flywheel spins and the impellers throw food against a stationary grind ring where it breaks into tiny pieces that wash down the drain.

When you hear humming the motor is receiving electricity and trying to turn the flywheel. The flywheel is not moving. That almost always means one of these causes:

• A jam. A bone or fruit pit or bottle cap or piece of silverware has wedged between the flywheel and the grind ring.
• A tripped overload protector. After a jam the motor overheats and a built in safety switch shuts it down. The red reset button on the bottom of the unit pops out when this happens.
• A seized flywheel. A disposal that sits unused for weeks can build up rust or hardened food that locks the flywheel in place.
• A failing motor or worn bearings. An old unit may hum because the motor no longer has the strength to turn the flywheel even when nothing is stuck.

The first three causes are cheap to fix and you can usually handle them in under twenty minutes. The fourth is the one that ends in a new disposal. The steps below help you work through them in the right order.

Humming vs Other Disposal Noises

A steady hum with no movement means a jam or a locked flywheel and that is what this guide covers. A loud rattle usually means a spoon or a bottle cap is bouncing inside so turn the unit off and remove it. Total silence means the motor is not getting power and you should skip ahead to the section on a disposal that will not turn on. If your garbage disposal is making a humming noise only for a second or two and then grinds normally the unit is fine.

Safety First Before You Touch Anything

A disposal can injure you badly if it starts while your hand is inside. Do not skip this part.

• Turn the wall switch off. Then cut the power fully. If the disposal plugs into an outlet under the sink unplug it. If it is hardwired turn off the circuit breaker that powers it.
• Never put your hand into the grinding chamber. Even when the power is off use tongs or pliers and a flashlight to pull out objects.
• Do not use chemical drain cleaners. They can damage the unit and splash back onto your skin and eyes. They are also dangerous if you later have to reach into the drain.
• Do not run the disposal while you are testing it by hand. Restore power only after your hands and tools are out of the sink.

With the power off you can work safely through the fixes below.

What You Need

You do not need many tools. Most of these are already in a kitchen or garage.

• A 1/4 inch hex key (also called an Allen wrench) that fits the socket at the bottom of the disposal. Many units ship with one. If you do not have it a basic hex key set costs a few dollars. This tool is often sold as a garbage disposal wrench.
• A flashlight
• Long tongs or needle nose pliers
• A wooden spoon handle or a short piece of broom handle
• Rubber gloves

Most disposals use a 1/4 inch hex socket on the underside but some brands use a different size. Check your owner’s manual or the label on the unit if the key does not fit.

Fix 1: Free the Flywheel With a Hex Key

This is the best first move for a garbage disposal humming but not working and it clears most jams. It works from below the sink so your hands stay out of the chamber.

1. Make sure the power is off.
2. Look under the disposal and find the small hex shaped socket in the center of the bottom plate.
3. Insert the hex key and push it fully into the socket.
4. Turn the key back and forth. Start with small motions and then try longer strokes. You are trying to rotate the flywheel by hand.
5. Keep working until the key turns freely in a full circle. You may feel a crunch or a pop as the stuck item loosens.
6. Remove the key and press the red reset button on the bottom (see Fix 4).
7. Restore power and run cold water. Flip the switch to test the unit.

If the key turns freely and the disposal runs normally the jam is cleared. If the key will not move at all you may have a heavily seized flywheel or an object lodged tightly. Move on to the next fix. This is also the method for how to fix a jammed garbage disposal when you cannot see what is stuck.

Fix 2: Turn the Blades From Above With a Wooden Spoon

Some disposals have no hex socket on the bottom. In that case you can turn the flywheel from above. The wooden handle works as a lever.

1. Confirm the power is off and the unit is unplugged or the breaker is off.
2. Shine a flashlight into the opening and look for the flywheel and the impellers.
3. Press the end of a wooden spoon handle or a broom handle against one of the impellers.
4. Push it to turn the flywheel one way and then the other way.
5. Keep rotating until it moves freely.

Use wood and not metal since a wooden handle will not damage the unit if it gets pinched. Never use your fingers for this. Once the flywheel turns freely restore power and test the disposal.

Fix 3: Remove the Object That Caused the Jam

Freeing the flywheel clears the symptom but the object that caused it may still be inside. Take a moment to remove it so the jam does not come back in a few minutes.

• With the power off shine a flashlight into the chamber.
• Look for bones and fruit pits and bottle caps and pieces of silverware or any hard item that does not belong.
• Pull each item out with tongs or needle nose pliers.
• Check around the rubber splash guard too since small items sometimes hide under it.

If you dropped a spoon or a fork down the drain recently that is a likely cause. You may hear a rattle after the jam clears. Turn the unit off again and keep looking until the chamber is clear.

Foods that most often cause a jam include fruit pits and animal bones and corn husks and celery strings and large amounts of potato peels. Rice and pasta can swell and form a paste that clogs the drain just below the disposal.

Fix 4: Press the Garbage Disposal Reset Button

If the unit hums and then goes silent or never hums at all the overload protector may have tripped. Almost every disposal has a reset button for exactly this reason.

Here is how to reset a garbage disposal:

1. Turn the power off at the wall switch.
2. Look at the underside of the unit and find the small red button. On most models it is near the bottom center or on the side close to the base.
3. Press the button firmly. It should click and stay in. If the button was already popped out it will push back in.
4. Wait about ten to fifteen minutes so the motor can cool down. A motor that overheated may refuse to reset until it has cooled.
5. Turn the power back on and run cold water.
6. Flip the switch to test the disposal.

If the button pops out again right away the motor is still jammed or overheating. Go back to Fix 1 and free the flywheel fully before trying again. If the button will not stay in no matter what you do the disposal may have an electrical fault.

Pressing the reset button over and over without clearing the jam can damage the motor. Do it once or twice and then look for the real cause.

Fix 5: Clear a Clog Below the Disposal

Sometimes the jam is not inside the grinding chamber. A clogged trap or drain line can make the disposal work hard and trip its overload protector. If the unit hums and shuts off and leaves standing water in the sink look downstream.

• Run cold water and watch how fast the sink drains. A slow drain points to a clog.
• Place a bucket under the trap and loosen the slip nuts and clean out the trap and the short pipe from the disposal.
• If you have a dishwasher check its drain hose and the knockout plug on the disposal inlet. A blocked hose can back water into the sink.

For drain problems that keep returning a plumber may need to look at the main line. Our plumbing repair cost guide shows what common drain and disposal repairs cost.

When the Garbage Disposal Is Not Turning On at All

If you flip the switch and hear nothing the problem is different. There is no hum so the motor is not getting power. A garbage disposal not turning on usually has a simple cause.

• Check the reset button. A tripped protector cuts all power to the motor and the unit stays silent. Press the button as in Fix 4.
• Check the wall switch. Flip it off and on a few times. A worn switch can fail.
• Check the outlet. If the disposal plugs in under the sink check that the cord is fully seated. Many sink outlets are protected by a GFCI (ground fault circuit interrupter) so press the reset button on the outlet itself.
• Check the circuit breaker. A tripped breaker is a common reason for a dead disposal. Flip it off and then on again.
• Look for loose wires. If you are comfortable doing so and the power is off at the breaker you can check the wire connections inside the disposal’s electrical plate. If you are not sure call an electrician.

If all of those checks are fine and the disposal is still dead the motor or the switch has likely failed.

When the Hum Means the Motor Is Dying

Sometimes you free the flywheel and press the reset button and the disposal still hums. The key turns freely and the chamber is clear but the motor will not spin. That points to a failing motor or worn bearings.

Signs the unit is finished include:

• The hex key turns freely but the disposal only hums when you flip the switch
• The reset button trips again right away even after the unit cools
• The unit is near or past the eight to fifteen year mark
• You see rust or water leaking from the bottom of the housing
• The disposal has needed several repairs in a short time

Most disposals last about eight to fifteen years depending on the brand and how much you use them. A cheaper model may last closer to the low end. When an older unit hums with no movement after a full reset the repair is rarely worth it. Replacing the unit is usually the better choice.

A new standard disposal often costs a few hundred dollars installed though the price varies by horsepower and brand and your location. Doing the installation yourself saves labor if you are comfortable with plumbing and basic wiring. If you are planning a larger kitchen update and want to know how a disposal fits into the budget see the kitchen remodel cost guide.

How to Keep a Disposal From Jamming Again

Consumer Reports has a useful guide on how to clean your garbage disposal that supports the habits below.

• Run cold water before and after grinding. Let it run for 15 to 30 seconds so food clears the drain and grease stays solid.
• Feed food in slowly and cut large scraps into smaller pieces first.
• Keep hard and fibrous items out. That means bones and fruit pits and corn husks and celery and large amounts of coffee grounds.
• Never pour grease or oil down the drain. It hardens in the pipes.
• Use the disposal regularly. A unit that sits idle for weeks can rust inside and lock up.
• Skip the metal and plastic. Silverware and bottle caps and twist ties do not belong in the sink.

Ice cubes and citrus peels can freshen the unit but they do not fix a jam or sharpen anything.

When to Call a Plumber

Call a professional when the hex key will not turn at all after repeated attempts or the reset button keeps tripping even after the flywheel turns freely. Call too if the disposal leaks or you smell burning or the sink keeps backing up. Expect a service fee plus parts or a replacement if the motor has failed. If a repair will cost more than half the price of a new unit replacement is often the smarter choice.

If you enjoy fixing things around the house our DIY home improvement guide explains which projects are safe to take on yourself and which are worth hiring out.

Frequently Asked Questions

Why is my garbage disposal humming but not working?

The motor has power but the flywheel cannot turn. A jam from food or a foreign object is the most common reason. A tripped overload protector or a seized flywheel or a failing motor can also cause it. Turn the power off and free the flywheel with a hex key and press the reset button.

How do I fix a garbage disposal that just hums?

Cut the power and insert a 1/4 inch hex key into the socket under the disposal and rotate it back and forth until it turns freely. Remove any object from the chamber with tongs and press the red reset button. Wait ten to fifteen minutes and then test the unit with cold water running.

Where is the garbage disposal reset button?

It is a small red button on the bottom or side of the unit near the base. Look under the sink with a flashlight. Press it firmly and wait for the motor to cool before turning the power back on.

Can I fix a jammed garbage disposal myself?

Yes. Most jams take about twenty minutes and need only a hex key and a flashlight and tongs. The key points are to cut the power first and never put your hand in the chamber.

How long does a garbage disposal last?

Most last eight to fifteen years. Heavy use and hard food scraps shorten that. A unit that hums after a full reset and a cleared jam is often at the end of its life.

Why is my garbage disposal not turning on?

If there is no hum at all the motor is not getting power. Check the reset button and the wall switch and the outlet and the circuit breaker. If all of those are fine the motor or the switch may have failed.

Should I use drain cleaner in a humming disposal?

No. Chemical drain cleaners do not fix a jam and they can damage the unit and create a safety risk. Clear the jam by hand with the power off.

Final Thoughts on a Garbage Disposal Humming

When a garbage disposal hums but will not spin stay calm and work through the steps in order. Cut the power and free the flywheel with a hex key or a wooden spoon and remove whatever caused the jam and press the reset button. Those four steps fix most humming problems at no cost.

If the unit still hums after a full reset or it is more than a decade old a replacement is the sensible next step. A little attention to what goes down the drain will keep your new disposal running smoothly for years.