A garbage disposal stops for one of three reasons. Something is jammed between the flywheel and the grinding ring, the motor has tripped its overload switch, or the drain below the disposal is clogged. All three can often be fixed in ten minutes with a flashlight and a hex key. The steps below go in order from the safest to the most involved.
If the unit is leaking from the bottom or still hums after every step, skip ahead to when to stop.
Before You Start: Cut the Power
Turn the wall switch off. Then unplug the disposal under the sink, or switch off its breaker if it is hardwired. Never put your hand inside the disposal, even with the power off. Use tongs or pliers to reach anything you see.
Step 1: Look for the Jam
Shine a flashlight down the drain opening. Bones, fruit pits, bottle caps, and silverware are the usual culprits. If you see something, pull it out with tongs. Fibrous food like celery, corn husks, and onion skins can wrap around the flywheel, so pull out any strands you can reach.
Step 2: Turn the Flywheel by Hand
Most disposals have a small hex socket in the center of the bottom of the unit. A 1/4-inch hex key fits it, and many disposals ship with one. Insert the key and work it back and forth until the flywheel turns a full circle freely. This frees a jam that you cannot see from above.
No hex socket on yours? Push a wooden spoon handle down the drain against one of the impeller lugs and rock the flywheel the same way.
Step 3: Press the Reset Button
When a disposal jams, the motor overheats and a built-in overload switch cuts it off. Find the small red or black button on the bottom of the unit. Wait about ten minutes for the motor to cool, then press it until it clicks.
Step 4: Test It With Cold Water
Restore the power. Run cold water at a steady stream, then turn the disposal on. If it spins freely and the water drains, you are done. Keep the water running for 20 to 30 seconds after the grinding stops to flush the line.
Step 5: If It Runs but the Sink Will Not Drain
A disposal that spins but leaves standing water usually points to a clog below it, in the P-trap or the drain line in the wall. Turn the power off again. Place a bucket under the trap, loosen the slip nuts, and clear the trap by hand. If the clog is past the trap, it is a drain cleaning job, not a disposal problem. Our kitchen drain cleaning page explains what happens next.
What Not to Do
- Do not pour chemical drain cleaner into a disposal. It can damage seals and gaskets, and it splashes back if the unit runs or someone opens the trap later.
- Do not run hot water while grinding grease. Grease melts, flows down the line, and hardens again further along, where it is harder to reach.
- Do not keep pressing reset if it trips right away. That is the motor telling you the jam is still there or the motor is failing.
When to Stop and Call a Plumber
Stop trying if you see any of these:
- Water leaks from the bottom of the unit. That usually means the internal seal or the housing has failed, and it cannot be repaired.
- The disposal hums but will not turn, even after the hex key spins the flywheel freely.
- The reset button trips again within seconds, or the breaker trips.
- Both sides of a double sink back up, or the dishwasher drains into the sink.
- The unit is more than ten years old and jams often.
In our experience, about eight out of ten disposal calls end in a replacement rather than a repair, because the failures above are inside the sealed motor housing. If you already bought a new unit, we can install the one you chose. Learn more about our garbage disposal repair in Sacramento.
Garbage Disposal Questions, Straight Answers
Is it safe to use a hex key on a garbage disposal?
Yes, it is, as long as the power is off. The hex socket on the bottom is designed for this. Turning it by hand cannot start the motor.
Can baking soda and vinegar unclog a garbage disposal?
No, not a real jam. Baking soda and vinegar can freshen a smelly unit, but they will not move a bone or a bottle cap. Clear the jam with the hex key first.
Why does my disposal hum but not spin?
It is usually a jam. The motor has power but the flywheel cannot turn. Cut the power and use the hex key. If the flywheel turns freely and the unit still only hums, the motor or its capacitor has failed.
How long should a garbage disposal last?
Most last about 8 to 15 years, depending on the model and how it is used. Units that grind a lot of fibrous food or grease tend to fail sooner.
Related Guides
- What a Sewer Camera Inspection Shows (and When You Need One)
- Plumbing Basics Every Homeowner Should Know
Still Stuck?
Send a photo of the unit and the label underneath, and we will tell you whether it is worth repairing before we come out. See our garbage disposal repair service.
