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Grinding Noise Coming From Garbage Disposal: Reasons and Fix

You’ve been using the garbage disposal under the sink in your kitchen for quite a while now without any problems. However, when you wanted to use it this morning, it made a grinding noise. You now want to find out whether you can keep on using the unit, what could have been the cause of the noise, how the problem can be fixed, and whether you can troubleshoot and fix it yourself. 

When your garbage disposal makes a grinding noise, stop using it until you’ve found the reason for the noise and fixed it. Usually, the noise is a result of an object obstructing the unit, and in most instances, you will be able to remove the obstruction yourself.  If it is a mechanical malfunction causing the noise, it is recommended that you call a plumber. 

Grinding noise from your garbage disposal and how to find and fix it

When you hear a grinding sound from the garbage disposal, stop using it immediately and don’t use it again before you’ve found the reason for the noise and fixed it. If you keep on using it, you might damage the device. 

General “rules” when inspecting your garbage disposal

Before we discuss the actual steps to find the cause of the noise and how to rectify it, let’s look at a few general rules when it comes to inspecting and repairing a garbage disposal.   

  • Remember, although there are no sharp blades in the disposal, the shredding ring and shredding impellers can still harm your fingers. 
  • So, always ensure that the garbage disposal is off before you start inspecting the unit. Unplug it, or if it is a hardwired model, put off the applicable circuit breaker. 
  • It is also recommended that you put on safety gloves so that you don’t cut yourself when you touch the shredding ring.
  • Never use force to remove an obstruction in the unit as you can damage the mechanical parts. If you can’t get it out, contact your local plumber or the garbage disposal manufacturer’s help desk.

The most common reason for a grinding noise

Usually, grinding noises indicate mechanical issues and are not signs that there is a fault with the electrical motor. The noise is in most instances caused by an obstruction preventing a smooth rotation of the mechanical parts. Usually, the grinding noise is an indication that there is hard material in the garbage disposal that can’t be ground and is jamming the moving parts. 

If it is an obstructing object

It is often a piece of broken glass or a small piece of metal, a kitchen utensil, or a hard bone causing the obstruction, but it is not always so easy to find and remove the object. Therefore, let’s look at some of the aspects to keep in mind when looking for the object. If you know what to look for, you might find the problem immediately, or if you don’t see the cause of the noise, you can follow the steps to find and remove the obstruction that is causing the grinding noise. 

Step 1: After you’ve put off the power to the unit and put on your safety gloves, reach down into the disposal with your fingers. If you feel something other than the rotating table and the shredding ring, try to take it out with your fingers. 

Step 2: If you can’t get the object out with your fingers, use a pair of long nose pliers and try to remove it. Don’t use force because you can damage the rotation table or shredding ring. 

Step 3: You can also try to remove the object with a vacuum cleaner. If the object is light enough, there is a possibility that the suction might lift it out of the unit.

Step 4: If you can’t get it removed, try to remove it from below. To do this, use the wrench that came with your garbage disposal. At the bottom of your garbage disposal, there’s a spot where you have to fit the wrench. After you’ve found the spot and fitted the wrench, turn it a few times. The object might now come loose and fall out. If you can see and feel the object but can’t get it out, your best solution is to call a professional.

If it is not an obstructing object

If you can’t see or feel any object obstructing the unit, you have to consider other reasons for the grinding noise. Other possibilities include the following:

  • A grinding component or another part might have become loose.
  • A loose bearing or rivet can also cause a grinding noise.
  • There might be clogs caused by improper foods, such as potato peels, or hard-to-grind foods in the disposal. 

When to call the plumber or the garbage disposal manufacturer’s help desk

If you cannot find any obstruction and the rotating metal turntable and shredding ring feel in position but you can’t rotate the turntable with your hand or the wrench, it is better to consult your plumber or the manufacturer’s help desk. The good news is that if the garbage disposal has broken completely, it is not too expensive to install a new one. And sometimes, the professional or plumber only has to replace a specific part.

Useful tips to keep your garbage disposal in good shape 

For your convenience, I’ve compiled the following two lists: a list of things that you should never put into the garbage disposal, and a list of the things you can safely put into the device.

Things you should never put into the garbage disposal

It is never good to put any of the following into the garbage disposal: 

  • Fruit pits;
  • large bones and shrimp shells;
  • nuts and banana peels;
  • pasta and rice;
  • onion skins, artichokes, potato peels and asparagus; or
  • cigarette butts and broken glass.

Things you can safely put into the garbage disposal

Generally, most soft and solid foods, such as vegetables and fruits, can be put in your garbage disposal. But sometimes, there are things you’re not sure whether you can put safely into the garbage disposal. The following list will give you peace of mind:

  1. Cooked meat scraps will not damage your disposal, but avoid big chunks which can block the chamber.
  2. You can put small, soft bones such as chicken bones in the disposal.
  3. Small citrus sections are safe, but try not to put fruit pits in the device. 
  4. Small amounts of coffee grounds can be put into the device, but large amounts should be avoided. A large amount of coffee grounds might create backups in the pipes due to the oils found in the grounds.
  5. Egg shells are “good” for your garbage disposal as they help clean the garbage disposal.

FAQs

Q1: What is the expected lifespan of a garbage disposal?

A1: Usually, garbage disposals will last between eight to twelve years if you use them correctly and keep them clean.

Q2: How do I maintain the garbage disposal in my kitchen?

A2: The best way to maintain your garbage disposal is to use it frequently. Always use cold water and ensure that the food scraps going down the disposal are not too large. Clean the device at least every two weeks.

Q3: How do I get smelly odors out of my garbage disposal?

A3: Cut one or two lemons, limes or oranges into wedges, place them in the garbage disposal, and run it.

Q4: Are there other garbage disposal noises that I have to be aware of?

A4: If the garbage disposal makes a loud and/or squealing sound, turn it off immediately. The sound can indicate a problem with the motor. If your device hums but doesn’t grind, the mechanisms aren’t functioning properly. This is likely caused by a jammed mechanism. In these instances, you most likely have to call a professional to attend to the problem.

Conclusion

Generally speaking, when your garbage disposal is making a grinding noise, it results from an obstruction in the unit. If you stop using the device immediately, it is usually possible to remove the object obstructing it before it can cause damage. In most instances, you can remove the obstruction yourself by following the steps outlined in this article.

If it seems as if the noise results from a mechanical issue, it is recommended that you call your plumber or the manufacturer’s help desk.  Fortunately, if your plumber has to replace some parts of the garbage disposal or even the unit as a whole, it will not be too expensive.  

My name is Thomas Anderson, author of DisposalQA. I have 15 years experience working as a plumber in CA, and this is where I answer common questions about garbage disposals.