Garbage Disposal Trouble: DIY Fixes and When to Call

Read the failure: hum, silence, or leak

A disposal tells you its problem by how it fails. If it hums but will not spin, it is jammed, with something wedged between the impeller and the housing. If it is completely dead, no hum at all, it has usually tripped its internal reset or lost power. If it spins freely but does not grind, the impeller is worn or broken. And if it leaks, the source is one of a few specific spots. Each of these points to a different fix, and two of them, the jam and the tripped reset, are often things you can handle yourself. Our garbage disposal repair and installation page covers the rest.

Clearing a jam safely

The humming jam is the most common problem and often a do-it-yourself fix, but safety first: never put your hand down a disposal, even when it is off. Instead, turn the disposal off at the switch, then look under the unit for a hex-shaped socket in the center of the bottom. Fitting the small hex wrench that came with the disposal, or the right size Allen key, into that socket and turning it back and forth frees the impeller by hand. Then press the reset button, usually a red button on the bottom, and try the disposal again. If it clears, you are done.

The one thing not to do is keep flipping the switch on a jammed disposal. That humming is the motor straining against the jam, and running it that way burns the motor out, turning a free two-minute fix into a replacement. If the hex trick does not free it, stop and call rather than forcing it.

Diagnosing a leak

A leaking disposal comes from one of three places, and where it leaks decides whether it is fixable. A leak at the sink flange on top, where the disposal meets the sink, is a seal that can be redone. A leak at the dishwasher hose connection is a clamp or hose issue, also fixable. But a leak coming from the body of the unit itself means the housing has corroded through, and that disposal needs replacing, no seal will fix a hole in the housing. Any of these can quietly pool water in the cabinet and warp the cabinet floor, so a disposal leak is worth sorting promptly rather than putting a bucket under it.

What a disposal can and cannot take

A surprising share of disposal breakdowns trace back to how it is used, and a bit of know-how heads off most of them. The repeat offenders are stringy scraps such as celery and corn husks, starchy piles of potato peel and pasta, coffee grounds, and grease, which either wind around the impeller or settle in the trap below and choke the drain. The single best habit is running plenty of cold water while the disposal works and for a few seconds after, which carries waste through rather than letting it settle. A disposal is not a trash can, and understanding its limits keeps a well-matched unit running for years instead of jamming every few weeks.

When it is really the drain, not the disposal

One thing worth knowing: because the disposal empties into the kitchen drain line, a clog downstream can make a perfectly healthy disposal seem to fail, backing up water into the sink when the disposal runs. If your disposal works but the sink drains slowly or backs up, the problem may be the drain line, not the disposal at all. Sorting out which one is the real culprit is part of a proper diagnosis, and it is why replacing a disposal that is not actually the problem does not fix a slow kitchen sink.