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Why Is My Garbage Disposal Humming?

The garbage disposal is a kitchen workhorse, minimizing odors from food scraps, reducing household waste, and ensuring debris doesn’t clog your pipes. Its smooth operation is crucial for hassle-free meal prep and post-dinner cleanup.

However, like any frequently-used appliance, it can face issues. A telltale sign of a problem is a persistent humming noise when the unit is on. This humming often indicates that the spinning plate inside isn’t moving as it should. But don’t fret; understanding the cause can lead to a quick solution.

In this guide, we’ll cover:

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If you want an established company you can trust to handle all your plumbing needs, Cooper Heating and Cooling has been in business for more than 45 years and offers highly trained, dependable technicians to service your home.

The Basics of How Garbage Disposals Work

Your garbage disposal is mounted between your sink’s drain and the pipes that lead to your septic system or the sewer. Its purpose is to break up food and debris washed down the drain to allow it to travel smoothly through your pipes, minimizing buildup and clogging. For homes with dishwashers, the drainage hose also leads to the garbage disposal to handle any food particles removed from your dishes during the wash cycle.

The grinding chamber of the garbage disposal has a disc, called the impeller plate, that spins rapidly to force food particles to the outer wall, breaking them up into finer pieces. Once the waste has been reduced, it can be flushed easily through your pipes.

Common Reasons for a Humming Garbage Disposal

The humming you hear comes from the disposal motor running without spinning the impeller plate. There are several reasons this could be happening, including:

  • Food buildup between the impeller blade and drain hole
  • The motor has overheated
  • A stuck object, such as a utensil, is preventing the impeller blade from turning

Steps to Troubleshoot a Humming Garbage Disposal

To figure out what is causing the humming issue, start by unplugging your garbage disposal so you can examine it safely. IMPORTANT: NEVER PUT YOUR HAND, LIMB, OR ANY TOOL OR OBJECT IN THE GARBAGE DISPOSAL WITH THE POWER ON. 

Check the drain hole to ensure no clogs are jamming up the impeller plate, and gently clean the area. Then, check down the drain into the grinding chamber to ensure there are no foreign objects caught in the unit. If you see something lodged, carefully remove it.

Next, turn the impeller plate or surrounding flywheel manually. This can sometimes be done with a hex Allen wrench through the breaker socket in the lower chamber. Otherwise, use a long tool to press down slightly on the impeller plate from above, rotating it gently to dislodge any jams and ensure it moves freely. If it turns easily, remove the tool, plug your garbage disposal back in, and turn it on to see if it works properly. If the humming continues, the problem may require a professional to repair.

Preventing Future Issues

To ensure your garbage disposal runs smoothly, it’s crucial to be mindful of what goes into it:

  • Avoid Water-Absorbent Foods: Items like pasta and rice can swell up, increasing the risk of blockages.
  • Beware of Coffee Grounds: They tend to settle and accumulate, leading to potential build-up.
  • Skip Hard Items: Bones, nuts, shells, and pits can harm the disposal mechanism.
  • Limit Stringy Foods: Onion skins, eggshell membranes, and fibrous fruits can wrap around the grinder, hampering its function.
  • Steer Clear of Fats and Oils: They can line the disposal’s interior, trapping food particles and causing residue build-up.

Always ensure water is running when the disposal is on; this helps wash away food particles. Additionally, clean your disposal bi-weekly: pour in a mix of 1/2 cup baking soda and 1 cup vinegar, let it sit for 10 minutes, then rinse with hot water. This simple routine can greatly extend the life and efficiency of your unit.

Take Advantage of Our Expert Plumbing Advice

Let the experts at Cooper Heating and Cooling help you stay on top of your garbage disposal or other plumbing repairs. We offer 1‑year renewable labor warranties, and our 100% satisfaction guarantee always backs our work.

Luke Cooper

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