Plumbing

How Does a Garbage Disposal Work?

THE MATERIAL CONTAINED IN THIS ARTICLE IS PROVIDED FOR GENERAL INFORMATION PURPOSES ONLY AND DOES NOT CONSTITUTE PROFESSIONAL ADVICE.LANDMARK HOME WARRANTY DOES NOT PURPORT TO BE A SUBJECT MATTER EXPERT WITH REGARD TO THIS MATERIAL, AND YOU SHOULD CONDUCT YOUR OWN RESEARCH AND/OR SEEK THE ADVICE OF APPROPRIATELY QUALIFIED PROFESSIONALS WITH REGARD TO YOUR SPECIFIC CIRCUMSTANCES BEFORE YOU TAKE ACTION. LANDMARK HOME WARRANTY ASSUMES NO RESPONSIBILITY, AND SPECIFICALLY DISCLAIMS ALL LIABILITY, FOR YOUR USE OF ANY AND ALL INFORMATION CONTAINED HEREIN.


Learn how a garbage disposal works with this downloadable diagram.

In 1927, a man by the name of John W. Hammes invented what he called the InSinkErator, which was installed in a sink's drain, took food waste, ground it up, and flushed it into waste lines. Now, almost nine decades later, many sinks have a garbage disposal included in their design and installed between the drain basin and the P-trap.

Although many homeowners have a garbage disposal, most don’t know how it works. Most homeowners picture a group of blades at the bottom of their sink, almost like a blender, liquefying the food waste that is put down the drain. Unfortunately, you can’t put just anything down a garbage disposal.

Garbage disposals can get jammed or burnt out when they’re used to dispose of items they can’t handle. The best way to avoid having your garbage disposal die before its intended lifespan is to understand how a garbage disposal actually works.

 If you look underneath your sink, you can see the body of the garbage disposal. It most likely looks something like the first image below. However, to understand how a garbage disposal really works, you have to look inside! Let’s take a look at what each part of a garbage disposal does to understand how it works

The inside and outside of a garbage disposal animated.

How the garbage disposal works.​​​​​​​

SPLASH GUARD

To understand how each part of a garbage disposal functions, start with what you see while looking at the garbage disposal when you’re using it. Your sink drain most likely has rubber flaps around the sides called a splash guard. These disposal flaps make sure that water and crushed food doesn’t splash back up into your sink basin.This is also where you put your food scraps into the disposal.

UPPER HOPPER

As your food scraps go into your disposal, they land in what is called the upper hopper chamber. When you put food scraps down the drain, you want to make sure you are running the garbage disposal with water running into the upper hopper at the same time. a

A diagram of a garbage disposal.

How the garbage disposal works.

FLYWHEEL, SHREDDER RING, IMPELLERS

Inside of the upper hopper, there is the shredder ring and the flywheel. The flywheel has two impellers on the sides of the wheel. The wheel is turned by an insulated motor at the bottom of the garbage disposal. The shredder wheel is a sharp, stationary piece of metal that has grooves and teeth. As the flywheel is spun by the motor, any food and water that is put into the upper hopper chamber is spun by centrifugal force into the shredder ring and pushed up onto the ring by the impellers.

WASTE LINE

Then, as the food waste is ground into manageable pieces, the water that is flowing down into the hopper moves the pieces into the waste line, down the p-trap, and out to the water treatment plant or the home’s septic tank.

Click to download the garbage disposal diagram.

How the garbage disposal works.

HOME WARRANTIES COVER GARBAGE DISPOSALS

 Now that you know how a garbage disposal works, you should make sure you know how to fix a jammed garbage disposal. Even if your garbage disposal isn’t clogged, you should ensure that you are doing preventative maintenance on the unit to keep it running as long as possible. This means cleaning it, which can also eliminate odd smells from the unit. If your garbage disposal fails for a covered reason and you have a Landmark Home Warranty plan, you could have your garbage disposal repaired or replaced it the cost of a service call fee. Compared to the average $400 you would pay for parts and labor from a plumber paying a service call fee of $60-$100 to get the garbage disposal fixed is a great deal! If you’re interested in getting a home warranty plan from Landmark, take a look at Landmark’s plans, or order home warranty coverage.

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