How to Clean Your Garbage Disposal

Disassembled garbage disposal.
credit: Home Drain Service
Things can get pretty grungy inside a garbage disposal.

Depending on whether you live north or south of the 49th parallel, you may call the kitchen appliance that grinds up your food waste a "garburator" or a "garbage disposal." Manufacturers sometimes like to call the appliance a "food disposer" or "food waste disposer." Whatever you call it, this little appliance hidden under your sink needs periodic TLC to do its job properly. Even if you avoid putting in types of food waste you know will clog it, a garbage disposal is bound to jam up at some point. That's a fact of life with garbage disposals, and the ability to clear jams is a skill every homeowner with a garbage disposal should have. Then there's the odor of rotting food that gets stuck in the blades, and the mold that feeds on it. They can make your sink smell like...well, like a site for where garbage is disposed. So cleaning a disposal is sometimes a matter of cleaning clogs and sometimes a matter of cleaning away smells....and sometimes both.

Manufacturer- and plumber-recommended cleaning regimens are surprisingly easy, so you won't have to expend much time or effort cleaning your garbage disposal, even if there's a clog that is preventing it from working. It's also very important to know kinds of waster your garbage disposal can handle and what it can't. Many waste items that are bad for your garbage disposal are also bad for your waste pipes and your septic system.

Know Your Garbage Disposal

Expanded view of a garbage disposal.
credit: Herrmann Services
Despite what you might think, a garbage disposal doesn't have spinning blades.

When you turn on your garbage disposal, you hear the sound of something rotating rapidly, but that isn't a set of blades cutting up the food. A garbage disposal doesn't work like a blender. The whirring sound you hear is a flywheel to which are attached a pair of impellers whose job it is to force the waste against the shredder ring, which works like a kitchen grater. It reduces the food waste to a pulp that gets washed down the drain by the stream of water that should always be running when the garbage disposal is on.

Sticky and greasy food waste can get stuck in the shredder ring, while stringy and bony waste can get wedged in the gap between the flywheel and the shredder. Most garbage disposals have an automatic disconnect that shuts off the power when the flywheel gets stuck. On these models, you'll find a reset button, usually red, located on the side or bottom of the canister. But before you press it and restore power, you have to clear the blockage, or the garbage disposal will shut off again when you start it.

Cleaning the Shredder Ring

Garbage disposal filled with ice cubes.
credit: Narrow Path Plumbing
Grind ice cubes once every few months to clean the shredder ring.

One leading manufacturer of garbage disposals recommends grinding ice cubes as a preventive measure, but not to sharpen the blades—because there aren't any. The purpose of the ice is to harden greases and starches clogging the shredder and to knock off the hardened deposits. For this to work, the ice cubes have to be as cold as possible. Fill the canister completely with ice cubes fresh out of the freezer, then pour in 1/2 cup of coarse salt to lower the melting point. Let the ice sit for about 30 minutes, then turn on the garbage disposal and the faucet and leave both on until all the ice and salt are gone.

Deodorizing and Disinfecting

Putting an orange in the garbage disposal.
credit: Insinkerator
Grinding citrus fruit cleans and deodorizes your garbage disposal.

Adding lemon juice to the ice and salt mixture will disinfect and deodorize the inside of the disposal hopper. Another way to get the deodorizing benefit of citrus juice is to cut a lemon, orange or lime into wedges and put it in the hopper before you fill it with ice. You can also simply grind the fruit by itself without the ice. Cut it into wedges and drop each wedge individually into the garbage disposal with the water running. You can even use a peach, pit and all. The pit will make a lot of noise, but it will do the same abrasive cleaning job that ice cubes do.

You can also use the familiar baking soda-and-vinegar "foamnado" technique to deodorize your garbage disposal. Pour 1/3 cup of baking soda in the garbage disposal and follow this with 1/3 cup of distilled white vinegar. The combination creates a volcano of foam that will probably overflow and fill the bottom of the sink. The foam is caused by the release of carbon dioxide as the acidic vinegar reacts with the alkaline baking soda. Leave it for about 10 minutes, then flush the mixture down the drain with water.

Don't forget the mouth of the garbage disposal. Food residue often collects there, and mold can also grow. Remove the rubber baffle every few weeks and wipe it down with a sponge and a little dish detergent and water. You can also put it in the dishwasher. Use a sponge or rag to wipe down the rim of the garbage disposal opening.

Unjamming a Garbage Disposal

Unjamming a Garbage disposal.
credit: Efficient Plumbing Services
Manually spin the rotor to free the obstruction before pressing the reset button.

When something hard, such as a bone, wedges between the rotor and canister, the unit jams and most disposals will automatically shut off. To release the jam, you have to spin the rotor back and forth. Many garbage disposals have a hexagonal slot on the bottom. Slip a 1/4-inch hex wrench—or the offset key that came with the disposal— into this slot and turn the rotor back and forth. When you are able to move the rotor freely in both directions, press the reset button, turn on the water and turn on the garbage disposal. You might hear some noise as the machine grinds what's left of the obstruction, but after that, the disposal should work normally.

Watch What You Put in the Sink

Cutaway of a garbage disposal.
credit: Anderson Plumbing, Heating & Air
Avoid putting starches, grease, and stringy foods in your garbage disposal.

Keep your garbage disposal happy by feeding it only what it can handle, and remember that what goes down the garbage disposal also goes into your plumbing and into your septic system, if you have one. It goes without saying you should never put harsh chemicals, including caustic drain cleaners, into a garbage disposal, especially if you have a septic system. You should also avoid stringy vegetables, such as celery and asparagus, because the strings can wrap around the rotor and cause clogs that are difficult to clear. The same goes for eggshells —they have a membrane that can also jam the rotor. Finally, avoid starchy foods, such as rice, pasta and potatoes, as well as grease. Both can collect on the shredder and clog it. Here are a few more things to avoid:

  • Onion layers and onion skins.
  • Coffee grounds. They can clog your pipes.
  • Nuts and shells. They dull the shredder and shorten the life of the garbage disposal.
  • Bones. Some units can handle small chicken bones, but even so, it's best to throw them in the trash.