Fix a garbage disposal that hums
We'll confirm the symptom, shut off power, then clear jams with the hex key, check the reset button, and remove obstructions—or tell you when to replace the unit.
What you'll need
- Hex key (Allen wrench) — usually included with the disposal
- Flashlight
- Wooden spoon or broom handle (for stubborn jams)
- Tongs or pliers (to remove objects; never use your hand)
Step-by-step diagnostic
Quick triage — pick your path
Get started
Choose the option that matches what you see. You can jump straight to that section.
- Follow this guide Work through the full procedure from confirming the symptom to testing.
- Shut off power first You need to shut off power before any repair.
- Clear a jam with the hex key You know the disposal is jammed and want to clear it.
- When to call a pro You cannot clear the jam, the unit leaks, or you are not comfortable with the repair.
Show full guide
Steps
Goal: Confirm the symptom first, then shut off power and clear the jam or replace the unit.
- Turn on the disposal at the wall switch. If it hums but the impellers do not turn, you have a jam or burned motor.
- Symptom confirmed: Hum only, no grinding—proceed to Shut off power first.
- No problem: Impellers spin and grind—unit is working. No action needed.
- Before any repair, unplug the disposal or turn off the circuit breaker.
Shut off power first
Goal: Confirm power is off before working on the disposal.
- Unplug the disposal from the outlet under the sink, or turn off the circuit breaker that feeds it.
- You should see no lights or sounds when you flip the wall switch.
- When power is off, you can safely work on the unit.
Reset and clear jam with hex key
Goal: Press the reset button and use the hex key to manually turn the impellers and clear jams.
- Press the reset button on the bottom of the disposal firmly.
- Insert the hex key into the hole on the bottom. Turn it back and forth to rotate the impellers and break free a jam.
- Good: The hex key turns freely after a few rotations—jam cleared. Restore power and test.
- Bad: The hex key will not turn—severe jam or burned motor. Inspect for obstructions or replace the unit.
Remove obstructions
Goal: Inspect the grinding chamber and remove visible objects without putting your hand inside.
- Shine a flashlight into the chamber from above. Look for silverware, bones, or other objects.
- Use tongs or pliers to remove objects—never your hand.
- If the hex key did not free the jam, insert a wooden spoon or broom handle and gently rock it against the impellers. Do not use metal.
- Good: Objects removed and impellers turn with the hex key. Restore power and test.
- Bad: Still stuck—motor may be burned out. Replace the unit or call a pro.
When to get help
Call 911 if you see sparks, smoke, or fire at the disposal.
Call a plumber if:
- You cannot clear the jam after trying the hex key and removing obstructions.
- The disposal leaks at the mounting or drain.
- The wiring is damaged.
- You are not comfortable working with electrical or plumbing under the sink.
- The unit is hard-wired and you do not know how to safely disconnect it.
Verification
- The disposal grinds normally when turned on with cold water running.
- No humming without grinding—impellers spin as expected.
- No leaks at the mounting ring or drain connection.
- The reset button sits flush and has not tripped again.
Escalation ladder
Work from the device outward. Stop when the problem is fixed.
- Confirm symptom Verify the disposal hums but does not grind; rule out a different problem.
- Reset and hex key Press the reset button and use the hex key to manually turn the impellers.
- Remove obstructions Inspect the chamber and remove visible objects; use wooden spoon for stubborn jams.
- Test and replace Restore power and test. If it still hums, the motor has burned out—replace the unit.
- Call a pro Sparks, smoke, or fire—call 911. Jam cannot be cleared, unit leaks, or wiring is damaged—call a plumber.
What to capture if you need help
Before calling support or posting for help, have these ready. It speeds everything up.
- Whether the reset button was tripped
- Whether the hex key could turn the impellers
- Any objects found in the grinding chamber
- Steps already tried
Does the disposal hum but not grind?
Turn on the disposal at the wall switch. A hum with no grinding means the motor is getting power but the impellers are not turning.
You can change your answer later.
No action needed
Is power shut off before repair?
Always unplug the disposal or turn off the circuit breaker before working on it.
You can change your answer later.
Shut off power first
Did you press the reset button?
The red reset button on the bottom trips when the motor overloads. Press it to reset.
You can change your answer later.
Press reset and try hex key
Does the hex key turn the impellers?
Insert the hex key into the hole on the bottom. Turn back and forth to free a jam.
You can change your answer later.
Can you remove visible obstructions?
Look into the chamber with a flashlight. Use tongs or a wooden spoon—never your hand.
You can change your answer later.
Restore power and test
Replace the disposal or call a pro
Reviewed by Blackbox Atlas
Frequently asked questions
- Why would a garbage disposal hum but not grind?
- Common causes: a jam (object stuck in the impellers), overload (motor straining), or a burned motor from prolonged overload. The hum means power reaches the motor; no grinding means the impellers are not turning.
- Can I fix a humming garbage disposal myself?
- Yes. Shut off power first. Press the reset button, use the hex key to manually turn the impellers and clear jams, and remove visible objects. If it still hums after all steps, the motor has burned out—replace the unit.
- When should I call a plumber for a garbage disposal that hums?
- Call 911 if you see sparks, smoke, or fire. Call a plumber if you cannot clear the jam, the disposal leaks, the wiring is damaged, or you are not comfortable working under the sink with electrical connections.
Rate this guide
Was this helpful?
Thanks for your feedback.