Garbage Disposal Making Loud Noise: Reasons & Fixes


It’s never fun to finish washing your dishes and turn on your garbage disposal, only for it to start making a loud noise. What could be causing this off-putting sound, and how can you make it stop?

If your garbage disposal system is making a loud noise, turn it off and unplug it before troubleshooting. A squealing noise means the motor is failing, while a whirring or humming noise usually means an object is stuck between the shredder ring and impellers. A grinding or rattling noise may be from a stuck object or loose impellers.

In this article, we’ll cover various reasons why your garbage disposal might be making a loud noise. We’ll also explain how to fix a noisy garbage disposal and how to know when your disposal needs to be replaced.

Why Is My Garbage Disposal Making A Loud Noise?

It can definitely be startling to hear your garbage disposal make a loud, unexpected noise when you turn it on! The cause of the noise can often be determined by its specific sound.

Squealing Noise

Unfortunately, if your garbage disposal is squealing, we have bad news for you. A squealing noise typically means the disposal’s motor is failing.

As soon as you hear a squeal come from your disposal, turn it off and unplug it. You’ll need to replace either the motor or the whole garbage disposal system.

Whirring Or Humming Noise

A humming or whirring noise coming from your garbage disposal usually indicates that something, whether that be food or another object, is stuck between the disposal’s impellers and the shredder ring.

These two parts both work to grind, cut, and shred large chunks of food into smaller pieces.

If you’re hearing a humming or whirring sound, then the motor is still running, but the impellers aren’t moving.

How To Remove A Stuck Object

When a stuck object is the root of the issue, it’s easy to fix. Turn off and unplug your disposal, and then use a flashlight and pliers to look for and remove anything stuck inside.

Plug in the disposal, turn it on, and run it again to see if the noise is gone. If you still hear it, then a malfunctioning flywheel could be to blame.

Fix The Flywheel

The flywheel is a disk-shaped metal mechanism that rotates. It’s attached to the impellers, so when the flywheel turns, the impellers turn as well.

You’ll need to turn off your garbage disposal. Then, look at the bottom and locate the hole in the center. Insert an Allen wrench into this hole and turn it from side to side until the flywheel moves smoothly.

Go back to the top of the disposal and remove any additional objects that were loosened. Then, plug in the disposal once again and run it to see if the noise is gone.

If it’s not, you may need to contact a professional or replace your garbage disposal altogether.

Loud Grinding and Rattling Noise

Turn off your garbage disposal immediately if you hear an abrasive grinding or rattling noise. There’s likely a foreign object in your disposal’s grinding chamber. 

You’ll need to unplug the disposal and remove the object as explained above. 

If there’s nothing stuck in the grinding chamber, then your disposal’s impellers may be loose. Locate the two bolts that secure the impellers and use a nut driver to tighten them up.

If you don’t feel like you have the expertise to do this, or if the noise persists, be sure to call a plumber for help.

Why Does It Sound Like There’s Metal In My Garbage Disposal?

If it sounds like there’s metal inside your garbage disposal, there are several possible explanations. The most likely is that a metal item is stuck inside the grinding chamber.

However, if you don’t see anything, the reason for the sound could be:

  • A stuck object that’s hidden from view
  • A loose rivet or bearing
  • Loose impellers coming into contact with each other
  • Another garbage disposal component that’s loose or broken

If you’re having a hard time troubleshooting, we recommend replacing your disposal or contacting a professional.

How To Fix A Noisy Garbage Disposal

Fixing a noisy garbage disposal involves checking for any items that could be jamming it and removing them. 

You’ll need to visually inspect the inside of the disposal (be sure to unplug it first) for any foreign objects or chunks of food. Remove them with pliers or a gloved hand.

You can also manually rotate the flywheel to dislodge any obstructions. Simply use an Allen wrench inserted into the hole in the center of the bottom of the disposal to turn it back and forth until it loosens up.

If these steps don’t eliminate the noise, the motor start capacitor or the motor itself may be the cause. 

Other potential issues could be a defective grinding ring or grinding plate.

In most cases, you won’t be able to buy individual replacement parts for these components, and it’s quicker and more cost-effective to replace the entire garbage disposal.

How Do I Know If My Garbage Disposal Needs To Be Replaced?

There are several indicators that your garbage disposal needs to be replaced.

It Gets Clogged Frequently

This usually means the blades are getting dull, or your garbage disposal is too small for your household’s needs. 

If you live in a three to six-person household, look for a disposal with a ½ to ¾ horsepower motor. For five to eight people, a 1HP motor is best. And for more than eight people, you’ll want up to 2HP.

You Have To Reset It Constantly

When you find yourself pushing the reset button on the bottom of the unit every other day, that’s a sign your disposal’s motor is getting weaker and should be replaced.

Poor Performance 

This indicates that the motor is weak or the blades are getting dull.

Leaks

This is a sign that there are multiple cracks inside your garbage disposal. These types of cracks are part of regular wear and tear, but once your disposal starts leaking, the entire unit needs to be replaced.

Loud Noises After Troubleshooting

If there’s nothing stuck inside your disposal and rotating the flywheel hasn’t helped, it’s likely the motor has died. Buying a new unit generally costs the same as replacing the motor, so we recommend replacing your garbage disposal altogether.

It Smells Terrible 

Although some unpleasant odors are normal with garbage disposals considering they deal with wet food waste, any unwanted smells should disappear with thorough rinsing and cleaning. 

If your disposal has lingering odors that you can’t seem to get rid of, it might be time to replace your disposal, or at least call a plumber to see if they can find any trapped food particles that are causing the smell.

Avoid using harsh chemical cleaners in an attempt to freshen up your disposal. They can cause damage to your disposal components and plumbing.

You’re About To Renovate

If you’re planning to renovate your kitchen, it’s smart to replace your disposal while you’re at it, even if it’s not yet failing. 

This is particularly true if you’ve had the same garbage disposal system for more than a decade, since most disposals have a lifespan of around ten years. 

Conclusion

When your garbage disposal makes a loud noise, your first instinct will probably be to troubleshoot, but be sure to turn off the disposal and unplug it first.

If the noise is more of a squealing sound, the motor is likely failing and needs to be replaced.

If it’s more of a humming or whirring, there’s probably an object stuck between the impellers and shredder ring that needs to be removed.

Finally, if your disposal is making a rattling or grinding noise, then the culprit could be a foreign object that you’ll have to remove or loose impellers that need to be tightened.

Jessica Allen

Jessica is a freelance writer and editor who has years of experience writing about home improvement and interior design. When she’s not typing away in her office, you can find her doing yoga in her backyard or curling up with a good book.

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