Garbage Disposal Humming but Not Spinning
That humming sound means the motor is getting power but the grinding plate can't spin. Something is jammed in there. This is one of the most common and most fixable kitchen problems... you can usually handle it in five minutes with a single tool.
What to Check Before You Call Someone
Turn it off immediately
If the disposal is humming, turn the switch off right away. The motor is trying to spin against a jam, and running it like this for too long will burn out the motor or trip the internal thermal overload.
Fix: Flip the switch off. Also make sure no one can accidentally turn it on while you're working on it.
Use the Allen wrench to free the jam
Every garbage disposal has a hex socket on the bottom center of the unit (under the sink). It's designed for exactly this situation. Most disposals come with an Allen wrench... if you lost it, it's usually a 1/4 inch hex key.
Fix: Insert the Allen wrench into the socket on the bottom of the disposal. Work it back and forth... you're manually rotating the grinding plate to free whatever is stuck. You should feel the resistance break free. This fixes the problem about 80% of the time.
Check for and remove foreign objects
With the power OFF, use a flashlight to look into the disposal from above. Common culprits: bones, fruit pits, broken glass, bottle caps, small utensils, or chunks of hard food that wedged between the grinding plate and the wall.
Fix: Use tongs or pliers to pull out whatever is in there. Never put your hand in a garbage disposal... ever. Even with the power off. If you can see the object but can't grab it, try the Allen wrench trick again to shift the plate.
Hit the reset button
On the bottom of the disposal unit (same spot as the Allen wrench socket, just nearby), there's a small red or black button. This is the thermal overload reset. If the motor overheated from running against the jam, this button will have popped out.
Fix: Press the reset button firmly until it clicks and stays in. Then try the disposal again with cold water running. If it pops back out immediately, the motor may have overheated badly... wait 15 minutes and try again.
Test the disposal
After freeing the jam and resetting, turn on cold water and flip the switch. It should spin freely. If it still hums and won't spin, the jam isn't fully cleared. If it does nothing (no hum, no sound), check the breaker or the reset button again.
Fix: If it works, run cold water and feed some ice cubes through it to clean the blades. If it still won't spin after clearing the jam and resetting, the motor may be burned out.
When It's Time to Replace
If the motor is burned out (you freed the jam, hit reset, and it still just hums or does nothing), it's replacement time. A new garbage disposal is $80-200 for the unit and about 30 minutes to install if you're handy... the hardest part is the plumbing connections. If the disposal is leaking from the bottom (internal seal failure), that's also a replace situation.
Read our full Garbage Disposal replacement guide →When to Call a Professional
Most people can handle this themselves, but call a plumber if you can't free the jam, if the disposal is leaking, or if you're not comfortable working under the sink with plumbing connections. If the disposal is hardwired (no plug) and you need to replace it, call an electrician unless you know what you're doing.
This guide is for informational purposes. For gas leaks, electrical issues, or emergencies, call a licensed professional immediately.