Many homeowners agree that once a garbage disposal is installed within the kitchen sink, they can't imagine life without the handy appliance. Disposing of food waste and cleaning up the kitchen has never been easier than with the help of a garbage disposal. No matter how useful and handy you find your disposal unit to be, though, things can happen to hinder its performance and longevity of life.
The average lifespan of a garbage disposal is between 8 and 15 years, depending on your care and maintenance practices. During this time, common issues like clogging and jamming can occur, especially if you treat your disposal like you would your trash can. When these issues happen, it is normal to hear strange noises coming from the unit. The most common of these noises is humming.
If you turn the switch to the disposal on only to be met by a humming noise, you might be tempted to pick up the phone and call your trusty neighborhood plumber. This is actually entirely unnecessary since in most cases a humming disposal can be fixed on your own without the need for a professional. Here you can read how to turn a humming disposal into your next DIY project.
According to a plumbing service located in San Diego, My Plumber CA, “there are three distinct noise issues that can happen in garbage disposals: a metallic rattling sound (often described like the firing of a machine gun), a whirring (humming) noise and a squealing sound.”
A disposal that makes a rattling, humming, or squealing noise is not happy for some reason or another. Here's what each type of unusual noise coming from a garbage disposal could mean, and whether or not you'll need to consider purchasing a new one.
Clanking or Rattling or Grinding
It’s never a good sign when you flip the garbage disposal switch to the “On” position, only to hear a clanking, rattling, or grinding sound. But don’t panic. This clanking, rattling, or grinding almost always means that a solid object is stuck within the unit. Luckily, this is a relatively easy fix.
Maybe a kitchen utensil fell down the sink drain, and the loud noise is simply the spoon, fork, or knife being bounced around by the disposal blades. This is one of the most common garbage disposal issues, and luckily, there is an easy fix. Simply turn the power off (always the first step) and use a pair of tongs or needle-nose pliers to remove the foreign object from the sink drain.
Buzzing or Humming
A humming disposal generally means that the unit is jammed up and the blades are unable to spin. Fixing a humming garbage disposal often requires more steps than remedying a rattling or clanking one. We’ll go into detail with a step-by-step guide on how to fix your humming garbage disposal in a bit.
A squealing noise coming from your garbage disposal typically indicates a more severe problem. As soon as you hear a squeal from your disposal unit, turn it off ASAP. The squeal could be telling you that the motor is failing or on the verge of failure. This tends to be a difficult fix, one that is best solved by shopping for brand new quiet garbage disposals.
Noise Reducing Technology
Nowadays, it is more than possible to install a garbage disposal that barely makes a peep as it runs. The top two brands for garbage disposals utilizing noise-reducing technology are Waste King and InSinkErator.
Waste King disposals are not only known for their powerful performance in grinding up and liquefying food, but also for remaining quiet while doing it. Noise reduction is one of the main priorities of the Waste King company, and they certainly have not failed in achieving it. Waste King models feature a noise-dampening case composed of nylon and glass, ensuring that noise remains at an all-time low.
Take the Waste King L-3300 disposal as an example. Its powerful motor spins at 2,700 revolutions per minute. Even so, the noise output still only reaches between 50 and 70 decibels. Maybe this decibel number means nothing to you, but all you need to know is that this noise level is much lower than the average garbage disposal on the market.
Anyone who has shopped around for garbage disposals in the past is probably familiar with the InSinkErator brand. This leading garbage disposal manufacturer is known for its high quality of products, as well as the quietness of products. InSinkErator disposals feature their patented SoundSeal technology, meaning their disposals barely make an audible noise as they operate.
If you thought the 50-70 decibel Waste King disposals were impressive, wait until you hear what InSinkErator has to offer. The maximum noise output for many InSinkErator products is a mere 45 decibels. This is the case for the InSinkErator Evolution Excel 1.0 hp Household Garbage Disposal. It is quiet yet powerful motor is tough on food scraps, but not tough on the ears.
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Benefits of Buying a Quiet Garbage Disposal
The most obvious benefit of installing one of the best quiet garbage disposals is the lack of noise you'll hear as you run your disposal. In other words, you'll never have to shout over to your husband sitting at the other side of the kitchen as the garbage disposal is running. And you'll never have to worry about waking your baby that is sleeping soundly in the other room. But quietness is undoubtedly not the only benefit.
The best quiet garbage disposals are also better than the environment than their noisier counterparts. They allow for the reduction of greenhouse gas emissions and cut down on noise pollution. On top of that, you’re more likely to use your garbage disposal when the noise coming from it is not deafening. This means a tidier kitchen and less chance of unpleasant smells coming from the rotting food that you threw in the trash can.
Step-by-Step Guide for Fixing a Humming Garbage Disposal
The humming sound coming from a garbage disposal could mean a few things. If the unit is humming, this is an indication that power is flowing into the unit, but the blades are not able to turn.
Scott English Plumbing, a plumbing company based in Orange County, says that “it is not uncommon that bits and pieces of food are the culprits. These could be stuck between the impeller blade and the drain hole causing the unit to jam."
Here's a step-by-step guide on how to go about fixing this common problem.
Step 1: Cut the Power
No matter if you are removing glass from your garbage disposal or attempting to determine the source of unusual noise, the first step is to turn off the power. Foregoing this vital task is just asking for a freak accident to happen. Don't just unplug the unit, but actually switch the main breaker to the "Off" position to ensure complete safety.
Step 2: Check the Disposal from Above the Sink First
If your disposal is humming, there is a good chance that it is clogged or jammed with a foreign object. Fibrous foods like stringy celery stalks and banana peels are a common culprit. Before you start fiddling with things below the sink, you can make it easier on yourself by checking things above first. You might find that something is stuck in the disposal that can be removed simply by reaching in with a pair of tongues or pliers.
Step 3: Manually Turn the Disposal Blades from Below the Sink
It isn’t often that the humming is solved after only completing step 2, but it is possible. However, if step 2 did not solve the issue, it is time to check out things below the kitchen sink. You’ll need to remove anything under the sink that might obstruct your access to the garbage disposal. Once you have access to the disposal unit, access the breaker socket located on the bottom side of the appliance.
This socket is where you'll insert an Allen or hex wrench and turn the disposal blades manually. Start by turning the wrench clockwise until resistance is felt. Once you feel the resistance, start wrenching in a counterclockwise motion, stopping once again when you feel resistance. Alternating between clockwise and counterclockwise will manually turn the blades, hopefully dislodging whatever is causing the problem.
Note: Not all garbage disposal models have the wrench socket for manually blade turning. If this is the case for your garbage disposal, you can use the backside of a broom handle to turn the blades instead. For this method, you’ll insert the handle into the sink drain and rotate the impeller blades back and forth from above the sink.
Step 4: Check for Normal Function
Once step 3 is done, you can check to see if your disposal is functioning normally. To do this, you'll need to turn the power back on and make sure everything is free and clear from the disposal. Then, turn the switch on to see what happens. As you do this, be sure that cold water is running. If the disposal functions as it should, clean your disposal and your work is done. If the humming persists, continue to the next steps.
Step 5: Remove the Disposal Unit if Necessary
For disposals that continue to hum even after steps 1 to 4, it may be necessary to remove the entire unit. This will give you a better understanding of what is going on. The Spruce says that “even small pieces of food can build up in the pipes and cause kitchen stoppages.” This is a common cause for humming, and a good excuse to remove the unit altogether.
Certain disposal units are easier to remove than others. The problem could be located in the disposal's drain trap, in which case you would use pliers to remove the trap. This will give you the chance to check for obstructions within the trap fitting and allow you to dislodge any blockages. If you must remove the entire disposal unit, it might be worth it to purchase and install a brand-new unit.
Step 6: If Removed, Reinstall the Unit
Once you’ve checked within the drain trap and the unit itself for clog obstructions that could be the cause of humming, it is time to reinstall. You can follow this garbage disposal guide from Lowe's to help out. Whether you install your existing disposal or opt for a brand new one, installation can be performed as a DIY project.
Things You Will Need
Whatever is causing your disposal to hum, clunk, grind, or rattle could be an easy fix. With a pair of needle-nose pliers, you can attempt to dislodge the cause of the noise from above the sink. This can also be done with a pair of tweezers or kitchen tongs. Before you try to fish anything out from the kitchen sink, be sure that the power is switched off.
An Allen-key (or hex-key) wrench allows you to turn the disposal blades without the use of power manually. This will be done by inserting the wrench into the Allen port located on the underside of the unit.
For disposals that have no port like the one described above, the back of a broom handle can be used to dislodge whatever is jamming or clogging the unit. A hammer handle can also be used to complete this task.
Seeing down the kitchen sink into the disposal can be challenging. A powerful flashlight can significantly help with this.
When to Call a Plumber
Almost all garbage disposal issues can be solved on your own without the help of a professional. However, you might want to call a plumber if you experience a squealing sound and hope to keep the current disposal. InSinkErator says that if your disposal is making an unusual noise like squealing, it could indicate that the motor of the disposal is failing.
A failing motor is extremely difficult to fix unless you are a professional engineer. In these cases, you might be better off scrapping your existing unit and purchasing a brand new one. This can be completed on your own without the help of a pro.
Hopefully, the steps above were able to remedy your garbage disposal's incessant humming noise. If you followed this step-by-step guide to no avail, it might be time to invest in a new garbage disposal unit. Luckily, there are plenty of powerful, quiet, and cost-efficient garbage disposals to choose from.
Holly Curell is the editor extraordinaire for Plumbing Lab. Having grown up in Michigan, Holly has spent time living in New York, Virginia, & currently North Carolina, where she lives with her husband & family. Holly loves DIY & has years of experience with at-home plumbing problems that arise from having 3 kids & living in colder climates. When she’s not writing about her plumbing knowledge, Holly enjoys reading, hiking & relaxing with family.