Nearly 50% of US residents have a garbage disposal installed in the kitchen.
A garbage disposal helps homeowners grind food waste to keep their kitchen fresh.
But if you neglect regular maintenance or overload the garbage disposal, it causes blockage and humming noise.
To fix the garbage disposal humming issue, you must identify what causes the unit to hum.
Fortunately, I will unravel the reasons for the hum and walk you through the troubleshooting steps to stop the noise.
Without further ado, let's dive in.
How To Fix Garbage Disposal Humming Issue?
The garbage disposal makes a humming noise when the unit gets clogged by obstructions or the motor gets jammed. The humming noise indicates that the unit receives power, but the impellers fail to spin.
To fix the humming issue, you need to release the blockage so that the impellers spin freely.
Here are the step-by-step guidelines you should follow to fix the humming noise and operate the garbage disposal like a charm:
Shut off the electric supply to your garbage disposal by unplugging the power cord or flipping down the circuit breaker.
Crawl down and locate the press button at the bottom of the unit.
Insert the Allen wrench into the center hole at the bottom of the disposal and rotate the wrench back & forth.
Keep rotating the Allen wrench until the blockage comes free, or turn the wrench one full revolution.
Use long-handled pliers to remove the blockage from the grinding chamber.
Restore power to your garbage disposal. Run cold water and turn on the disposal unit. Now, it should run.
Note: Use a flashlight if required to check the grinding chamber to identify any visible blockage. Sometimes, tiny objects like screws can get stuck in the small edges or grooves of the grinding ring. Use pliers to remove such tiny objects.
What Causes Garbage Disposal To Hum and How Do You Fix Them?
Obstructed blades, clog, or overheating are some reasons that cause your garbage disposal to make a humming noise.
1. Impellers (Blades) Get Obstructed
A garbage disposal has impellers mounted on the flywheel or shredder plate instead of sharp blades.
It indicates that the garbage disposal can't grind everything you throw in it.
If you throw non-food items like child toys, spoons, or screws in the disposal, the disposal blades get obstructed- instead of chopping up them.
When you turn on your garbage disposal, the electric current flows through the unit and the motor. The motor then tries to turn the blade, which causes a humming noise as it won't grind items except food items.
How To Fix:
Shut off your garbage disposal and cut the electric supply off to the unit by unplugging the power cord or flipping down the circuit breaker.
Reach into the garbage disposal using long-handled pliers to pull out the objects that cause blade obstructions.
Once you release the blockage from the grinding chamber, restore the power to your garbage disposal.
Run cold water and turn on the garbage disposal to verify that the disposal is running smoothly.
2. Disposal Gets Clogged
Putting things that garbage disposal can't handle causes clog in the disposal unit.
For example, if you throw fibrous foods like asparagus in the garbage disposal, they wrap around the disposal blades and cause a blockage.
Similarly, flushing oil, grease, and fats down the garbage disposal causes a restriction in the disposal and causes the blades to get stuck.
When you turn on the garbage disposal, the motor receives power. But the heck is, the disposal fails to grind the food waste because of the stuck blades, and you hear a humming noise as a by-product.
How To Fix:
To clear blockage, go along with the following steps:
Turn the power off to the garbage disposal.
Slide the Allen wrench into the central hole at the bottom of the unit and rock it back & forth to loosen the food waste buildup.
Use long-handled pliers to pull out the stuck or loosened particles.
Restore power to your garbage disposal.
Run cold water and turn on the disposal to flush down the disposal smoothly.
3. Overheating
A garbage disposal can overheat due to several reasons, including:
Blades are too dull, causing the garbage disposal to work for an extended period and overheat the unit.
Putting unprohibited items like fruit pits or non-food items that garbage disposal can't handle causes the disposal to get overheated.
A faulty motor can also lead the garbage disposal to overheat as the damaged motor can't grind the food waste properly and produce a humming noise.
Using the garbage disposal for an extended period without a break can cause the unit to overheat and create a hum.
How To Fix:
Try the following troubleshooting steps to fix the overheating issue:
Grind ice cubes and rock salt with your garbage disposal. This process helps sharpen the garbage disposal blades.
Never put food that your garbage disposal fails to grind. You can read this article to learn what not to put in garbage disposal.
If your garbage disposal unit overheats and creates a hum due to a faulty motor, I recommend you replace the garbage disposal as the repair cost will be the same as the replacement.
Don't overuse the garbage disposal.
4. GFCI outlet or The Disposal Gets Tripped
The GFCI outlet or the garbage disposal unit gets tripped, which may cause the unit to hum.
When the GFCI outlet gets tripped, the garbage disposal motor receives insufficient or no electric power. The lack of electric power is responsible for the humming noise as the disposal unit fails to turn the blades.
Similarly, every garbage disposal has a reset button. If that button gets tripped, the unit will hum when you activate it.
Generally, the reset button is a safety feature. If your garbage disposal gets overheated, it cuts the electric supply off by tripping the reset button.
How To Fix:
If the GFCI outlet gets tripped, reset it.
Second, reset your garbage disposal. You can find the reset button at the bottom of the garbage disposal.
Press the reset button. Afterward, turn on the unit and check it for proper operation.
5. Faulty or Jammed Motor
The average lifespan of a garbage disposal is between 10 to 12 years.
If your garbage disposal reaches its end stage, a defective motor will be a sign to replace the unit.
A garbage disposal motor gets faulty due to age, excessive wear & tear, and short circuit from wiring.
How To Fix:
Replacing the garbage disposal will be more cost-effective than repairing the unit.
For example, you need to hire a professional to repair or replace the defective motor as the repairing requires expertise. Hiring a certified plumber will cost you up to $100, let alone the cost of the motor.
On the other hand, a new garbage disposal requires $100 to $130 to get an entry-level disposal.
What Maintenance Tips To Follow To Prevent Garbage Disposal From Humming?
Follow these garbage disposal maintenance tips to prevent the unit from humming in the future:
Operate the garbage disposal regularly even if there is no food waste to grind. It keeps the moving components inside the unit functional.
Run a steady stream of cold water before, during, and after using the garbage disposal.
Clean the garbage disposal once a week to remove the buildup lingering inside the unit.
Grind ice cubes and rock salt periodically to sharpen the edges of the disposal blades (impellers).
Never put hard items like fruit pits regularly, as they dull the blades over time and decrease the grinding efficiency.
Don't put fats, oil, and grease in garbage disposal as they cause blockage.
Don't put fibrous foods like corn husks, asparagus, and celery in your garbage disposal.
Don't put non-food items like screws, plastic, glass, and child toys in the garbage disposal.
Explore the DIY Repair & Troubleshooting category to learn more hacks to fix your garbage disposal.