When you turn on your garbage disposal, you expect to hear a familiar grinding noise, not a hum. When this happens, it usually points to a unit that has power but won’t spin. This could be due to something stuck in the disposal, a jammed flywheel, or even a failing motor.
This article walks you through the many reasons a garbage disposal will hum instead of grind and how to safely fix the problem. There are some scenarios where a simple DIY fix will suffice, but others may need help from a trained plumber.
Here at Benjamin Franklin Plumbing of Niceville, we have an expert team of punctual plumbers who fix humming, jammed, and non-spinning disposals so your kitchen can run smoothly.
Quick Takeaways
- Humming noise means impellers aren’t moving
- Flywheel jams and objects often cause it
- Turn off power before inspecting anything
- Press reset button and free the jam
- Persistent humming signals possible motor failure
- Ignoring humming can burn out the motor
Why Is My Garbage Disposal Humming But Not Spinning?
A garbage disposal that hums but won’t grind normally points to a stuck or overloaded motor. This could be the result of jammed food debris, foreign objects, or other blockages that impact the blade movement.
Common Causes of a Humming Garbage Disposal
If you understand the things that normally cause a garbage disposal to hum, you can take faster action to prevent costly damage. Here are the most common contributors.
1. Jammed Flywheel or Foreign Object
There are lots of items that can get wedged between the impellers and shredder ring, including food scraps and utensils. When this happens, you may notice humming without grinding as well as slow draining. The lights may also flicker due to increased electrical strain.
How to fix:
- Shut the power off
- Look inside with a flashlight
- Use Allen wrench to free the flywheel
- Press reset button and test
2. Overloaded or Overheated Motor
The motor in the disposal can only handle so much load at a time. Running too much food or grease through the system may overwork the motor and cause it to hum instead of grind. It can also cause the unit to shut off mid-cycle.
How to fix:
- Let motor cool 10–15 minutes
- Press the red reset button
- Run cold water and test
3. Tripped Breaker or Loose Wiring
Sometimes, a garbage disposal won’t grind because it’s connected to a tripped breaker or loose wiring. This can easily happen when a circuit overloads and during remodeling.
How to fix:
- Check the breaker
- Check the plug connection
- Check the GFCI outlet
- If it persists, call a pro
4. Worn Motor or Internal Component Failure
The internal parts of a garbage disposal wear out over time, sometimes leading to worn bearings or a failing motor. This can make the disposal hum but not grind.
How to fix:
- Shut the power off
- Try the reset button
- Test after cooling the motor
- Get worn bearings replaced
- If humming stays, replace the unit
5. Poor Installation or Mechanical Misalignment
A low-quality installation risks misaligned mounting and loose connections that restrict impeller movement. This is why it’s so important to hire a skilled plumber to do the install for you.
How to fix:
- Turn off power to the unit
- Check for loose or misaligned parts
- Tighten mounting bolts and brackets
- If unsure, book a professional inspection
Step-by-Step Troubleshooting Guide (Safe DIY Fixes)
Anytime you work on the garbage disposal yourself, it’s imperative to take proper precautions to keep yourself safe. Being careful will also help prevent damage to the disposal that could cause further problems.
Step 1: Turn Off Power
Make sure the unit is powered off by flipping the breaker switch that it’s connected to.
Step 2: Check for Obstructions
Don’t ever use your hands to remove stuck items. Instead, use tongs. This way, if anything were to suddenly break loose, your hands won’t get injured.
Step 3: Manually Free the Flywheel
Use an Allen wrench by putting it into the hex socket at the bottom of the disposal. Rotate the tool clockwise to try and dislodge the jam. If successful, proceed to the next step. If not, call a professional.
Step 4: Press the Reset Button
Press the reset button on the disposal and wait 10 minutes before turning it back on. This gives the unit plenty of time to reset and cool its internal components so it can run properly again.
Step 5: Restore Power and Test
Turn on cold water (to help flush debris), flip the power switch back on, and check to see whether the unit hums or grinds.
When to Call a Professional Plumber
- Humming continues after reset
- Burning smell or smoke
- Breaker trips repeatedly
- Leaks, rust, or corrosion
- Unit over 10 years old
- Electrical issues need a pro
Prevent Future Humming Problems
- Run cold water during each use
- Don’t put hard or greasy items in the disposal
- Clean monthly with ice or vinegar
- Use often to prevent rust
- Schedule yearly plumbing checkups
FAQ – Common Questions About Humming Garbage Disposals
Why is my garbage disposal making a humming noise but not spinning?
When a disposal hums instead of grinding, it usually points to a jam or failing motor. It could also be the result of overheating that triggers the unit to shut itself down for protection.
Is it safe to keep using a humming garbage disposal?
No, it’s not safe. You should turn the unit off and get the problem fixed before using it again.
Can I fix a humming garbage disposal myself?
Yes, there are some minor issues that you can fix yourself so the unit will grind instead of hum. This typically requires pushing the reset button and using an Allen wrench to free jams. If you don’t feel comfortable or can’t get the blades moving again, you need to call a plumber.
How much does it cost to repair a humming garbage disposal?
The cost of repairing a humming disposal depends on the complexity behind the cause. Minor jams are usually inexpensive to fix. If we have to replace the motor or install a new unit, this can significantly increase the overall price.
How long does a garbage disposal last?
With proper care, your disposal should last anywhere from 8 to 15 years. If your home has hard water, the disposal will benefit from more regular cleaning to keep mineral buildup from damaging internal parts.
Stop the Humming with Niceville’s Punctual Plumbers
Don’t ever ignore a disposal that hums instead of grinds. If you do, you risk the motor burning out as well as damaging the internal components. Here at Benjamin Franklin Plumbing of Niceville, we offer installations, repairs, maintenance, and replacements for garbage disposals.
Our punctual plumbers bring professional expertise to every job. We’ll fix your disposal so it grinds properly and the blades move freely.
Go online today or give us a call to book an appointment with our skilled team of plumbers. We’ll arrive on time to fix your disposal so you can get back to using your kitchen with confidence.