If your garbage disposal hums when you turn it on but doesn’t grind food, it can be frustrating and concerning. The good news is that this problem is very common and is often caused by a simple mechanical issue rather than a broken unit.
Understanding why your garbage disposal is humming can help you fix the problem safely and avoid costly replacements.
Garbage disposal under kitchen sink that hums but does not work
What Does It Mean When a Garbage Disposal Hums?
The humming sound means the disposal motor is receiving power, but the grinding mechanism inside is not moving. This usually happens when something is jammed or the disposal has overheated and shut itself off.
Common Reasons a Garbage Disposal Hums
1. Jammed Disposal (Most Common Cause)
Food scraps, utensils, or hard debris can jam the grinding plate.
Common causes:
- Bones or fruit pits
- Silverware or bottle caps
- Hard food scraps
When jammed, the motor hums but cannot spin.
2. Overheated Motor
If the disposal has been running for too long or is overloaded, it may shut off automatically to prevent damage.
Signs:
- Disposal hums briefly or not at all
- Stops working suddenly
Most disposals have a built-in reset button.
3. Electrical Issue
If power is reaching the disposal but it can’t operate properly, wiring or switch issues may be involved.
Signs:
- Humming is inconsistent
- Disposal works sometimes and not others
4. Worn or Damaged Internal Parts
Older disposals may have worn components that prevent the grinding plate from moving freely.
In this case, repair may not be cost-effective.
How to Fix a Humming Garbage Disposal (Safe DIY Steps)
⚠️ Always turn off power at the switch or breaker before working on a disposal.
Step 1: Turn Off Power
- Switch off the wall switch
- Unplug the disposal (if accessible)
Never reach inside while it has power.
Step 2: Check for Obstructions
- Use a flashlight to look inside
- Remove visible debris with tongs or pliers
- Never use your hands
Step 3: Use the Reset Button
- Locate the red reset button under the disposal
- Press it firmly
- Restore power and test
This fixes many humming problems.
Step 4: Manually Rotate the Disposal
Most disposals have a hex socket underneath.
- Insert an Allen wrench
- Turn it back and forth to free the jam
- Restore power and test
When Should You Replace the Disposal?
Replacement may be necessary if:
- The motor continues humming after resets
- The unit leaks
- The disposal is over 10 years old
- Repairs cost more than replacement
When to Call a Professional
Call a plumber or electrician if:
- You’re uncomfortable working near electrical components
- The disposal won’t reset
- There’s burning smell or sparks
Safety should always come first.
Final Thoughts
A humming garbage disposal is usually a sign of a jam or overheated motor. In many cases, simple steps like removing debris or pressing the reset button can restore normal operation.
Addressing the issue quickly can prevent further damage and extend the life of your disposal.