Advice on the reasons for a humming garbage disposal and expert DIY tips for some quick fixes. 

Is your garbage disposal humming, but not grinding when you flip on the switch? This common home improvement can usually be resolved pretty quickly with a bit of basic troubleshooting. The following step-by-step instructions will help you tackle the problem and get your disposal running smoothly.

When a garbage disposal makes a humming sound instead of grinding up food particles, it has overheated, jammed, or has a mechanical issue. Here’s what to do for each of these possibilities:

Garbage Disposal Has Overheated

  1. Feel the underside of the disposer. If it’s warm, the disposer may have overheated. When this happens, many models automatically shut off to protect the motor—and they have a reset button.
  2. Look for the red or black reset button. This is usually located on the bottom of the disposal (see the illustration). If your disposal has a reset button, push it to reset the disposal.
    A hand using a hex wrench to manually rotate clogged garbage disposal impellers.
    Press reset button to restore power. Hex wrench turns blades to dislodge a jam (discussed below). Don Vandervort, HomeTips © 1997 to 2023 | HomeTips
  3. Just press the button firmly and try the disposer again. If it works, congrats! If the garbage disposal is still humming but not turning on, keep reading.

Garbage Disposal Is Jammed

When the reset button doesn’t clear up your issue, the unit might be jammed. The rotating blades inside the disposal—also called the impeller—can sometimes become jammed by food waste like bones, nuts, or foreign objects like a bottle cap. If the impeller and blades can’t turn, the motor will lock up and hum without grinding. If you leave the switch on too long in this situation, the motor will probably burn out—so turn the switch off quickly. Then:

  1. Turn off the power to the unit. Either unplug the disposer from its electrical outlet or locate the electrical circuit breaker that protects the disposal’s electrical circuit and turn off the circuit breaker. Always make sure the power is turned off before attempting any repairs.  Also see How to Turn Off Your Home’s Electricity.
  2. Use a hex wrench. Most garbage disposals come with a ¼-inch hex (Allen wrench) that’s designed to free-up a jammed impeller from the bottom of the disposal. Insert the wrench into the small hexagonal hole located at the center of the disposal’s bottom as shown above. Crank the wrench back and forth to manually loosen any objects causing the jam.
    1/4-inch metal hex wrench.
    Inexpensive garbage disposal wrench clears a jammed disposer. In-Sink-Erator
  3. If you don’t have a hex wrench, make sure the power is disconnected and put a short broomstick into the disposal. Push it down against one of the blades, and try to rotate the impeller back and forth to free the jam.
  4. Remove any visible obstructions that are dislodged. The disposal has sharp blades inside, so use long-nose pliers or tongs—do not stick your hand in it—to retrieve objects.
  5. Restore power and test. After freeing up any jam, restore power to the disposal by plugging-in the unit or flipping the circuit breaker or switch back on. Then see if the disposal works properly by turning it on again.

Mechanical Issues

In some cases, your garbage disposal may hum but the blades are not jammed with something lodged inside. This is generally bad news, because it usually means the motor has burned out or some other mechanical parts have broken down. Garbage disposal replacement, which typically costs $180 to $410, is usually cheaper and more sensible than trying to repair a broken disposal.

If it’s time to replace your garbage disposal, see the HomeTips Garbage Disposal Buying Guide.

​​For more about garbage disposal repair, see How to Fix a Garbage Disposal


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About Don Vandervort
Don Vandervort has developed his expertise for more than 30 years as a remodeler and builder, Building Editor for Sunset Books, Senior Editor at Home Magazine, author of more than 30 home improvement books, and writer of countless magazine articles. He appeared for 3 seasons on HGTV’s “The Fix,” and served as MSN’s home expert for several years. Don founded HomeTips in 1996. Read more about Don Vandervort