Garbage Disposal Dos and Don'ts

Most garbage disposal service calls we get across Los Angeles aren't mechanical failures. They're caused by what people put down the drain. A disposal is a powerful tool, but it has limits — and most homeowners learn those limits the hard way, usually on Thanksgiving or during a dinner party when the sink backs up and the kitchen grinds to a halt.

What a Garbage Disposal Actually Does

A garbage disposal doesn't have blades. It has impellers — spinning lugs mounted on a plate that force food waste against a stationary grind ring, breaking it into particles small enough to wash through your drain pipe. Understanding this changes how you think about what goes in.

It's a grinder, not a blender. It can't liquefy food. It can't handle anything that doesn't break apart easily under centrifugal force and pressure. Anything stringy wraps around the mechanism. Anything too hard jams it. Anything starchy or greasy clogs the drain line downstream — and that's a bigger problem than the disposal itself.

What You Should Never Put Down a Disposal

Grease, oil, and cooking fat. This is the number one cause of kitchen drain clogs in Los Angeles. Grease goes down liquid, coats the inside of the disposal and drain pipe, then hardens as it cools. Over time it builds up into a solid blockage that no amount of hot water will clear. Bacon grease, pan drippings, butter, coconut oil — all of it goes in the trash, not the sink.

Pasta, rice, and bread. These expand with water. Pasta and rice continue absorbing moisture after they go down, swelling inside the drain trap and creating a starchy paste that blocks flow. A handful of spaghetti can shut down a kitchen drain in hours.

Coffee grounds. They seem fine going down — small, granular, already wet. But coffee grounds accumulate in the drain trap and pack together into a dense sludge that restricts water flow. One pot of grounds won't kill you. A daily habit will.

Bones and fruit pits. Chicken bones, peach pits, avocado seeds, cherry pits — these are too hard for the impellers. They bounce around inside the chamber, jam the mechanism, and can burn out the motor. Small fish bones are generally fine. Everything else goes in the trash.

Fibrous vegetables. Celery, artichoke leaves, corn husks, asparagus stalks, and onion skins. The long fibers in these foods wrap around the impellers and grind ring like string around an axle. The disposal can't break them down — it just gets tangled.

Egg shells. The shell itself breaks up fine, but the thin membrane inside wraps around the grind ring and impellers. Over time this buildup restricts the mechanism.

Potato peels. Thin enough to slip past the impellers without being ground, thick enough to accumulate. The starch creates a gluey paste in the drain that hardens into a blockage.

Paint, chemicals, and grout. These damage the disposal's internal components and contaminate the water system. Never pour anything down a disposal that you wouldn't pour down a regular drain.

What's Actually Fine to Put Down

Small soft food scraps — the stuff that comes off plates when you rinse them. Cooked vegetables, soft fruits, small pieces of meat or fish, citrus peels (these actually clean and deodorize the disposal), and ice cubes (they knock debris off the impellers and clean the chamber).

The key rule: run cold water before you turn the disposal on, keep it running while you feed waste in slowly, and let it run for 15 seconds after you're done. Cold water — not hot. Hot water liquefies grease, which then travels down the pipe and hardens further along. Cold water keeps grease solid so the disposal can break it up and flush it through.

How to Keep Your Disposal Running for Years

Always run cold water. Hot water is the wrong choice. Cold water solidifies any grease so it gets ground up and flushed instead of coating your pipes.

Run it regularly. Even when you don't have food waste. A disposal that sits unused corrodes and seizes. Run it with water for 10 seconds every few days to keep the mechanism moving freely.

Clean it monthly. Drop a handful of ice cubes and a tablespoon of coarse salt into the disposal and run it for 30 seconds. The ice and salt scour the impellers and grind ring. Follow with a few citrus peels for a natural deodorizer.

Never use chemical drain cleaners. Drano and similar products corrode the disposal's internal components and shorten its life dramatically. If you have a clog, call a plumber or use a plunger.

Don't overload it. Feed waste in gradually. Shoving an entire plate of food down at once overwhelms the motor and jams the mechanism. Small amounts, steady flow, cold water running.

When It's Time to Replace

If your disposal leaks from the bottom, the internal seal has failed — that's not repairable. If it resets constantly, the motor is overheating and dying. If it takes longer and longer to grind the same amount of food, the impellers and grind ring are worn out.

Disposal replacement is a 30–60 minute job for a licensed plumber. Repair usually isn't worth it — by the time the motor or seals are failing, the rest of the unit is close behind. A new quality unit runs $150–350 installed, which is less than most people spend on a single drain cleaning emergency call.