Quick Answer:
If the impellers won’t turn, first cut power and check whether the grinding plate will move at all. Most jams are caused by a small object wedged between the impellers and the grind ring; removing the object or freeing the plate usually restores normal function.
Why This Happens
- Foreign object (utensil pieces, glass, toothpicks, bottle caps) caught between the impellers and the grind ring.
- Motor overload or thermal trip after a jam—motor may hum but not turn.
- Broken internal parts, seized bearings, or a snapped shaft in older units.
- Incorrect wiring or switch issues after recent work—if you recently changed a switch and the unit hums, see Disposal hums after installing new switch.
Step-by-Step What to Do
Step 1 — Kill the power
- Turn the disposal off and remove power at the circuit breaker or unplug the unit. Never work with the unit live.
- Confirm power is off by trying the wall switch: it should do nothing.
Step 2 — Try to move the grinding plate manually
- From the bottom: many disposals have a small hex socket at the center of the unit. Insert the manufacturer-supplied hex key (or a correct-size Allen wrench) and turn gently back and forth to see if the impeller plate moves.
- From the top: do not put your fingers inside. Use a non-metal tool (a wooden spoon handle) to try a gentle nudge on the impellers to feel for movement.
- With power off, test whether the impeller plate can move at all; if it turns freely with the hex key, the jam may be cleared.
Step 3 — Inspect for a wedged object
- Use a flashlight to look down the drain. If you see a foreign object, remove it with needle-nose pliers or long tongs—still with power off.
- A wooden or plastic stick is safer than metal for nudging small items free.
Step 4 — Reset and test
- After freeing the plate and removing debris, restore power and press the disposal’s reset button if your unit has one. If the reset button pops repeatedly, troubleshooting the motor or wiring is next—see Disposal won’t reset.
- Turn the unit on briefly (with cold water running) to confirm normal operation. If it still hums or doesn’t start, stop and reassess.
Step 5 — If it won’t move or parts are damaged
- If the grinding plate won’t budge with the proper hex key, or you see broken metal pieces inside, stop and consider professional help (see below).
What Not to Do
- Do not force rotation with improvised tools that can damage the grind ring.
- Do not put your hand or bare fingers into the disposal throat.
- Do not pour chemical drain cleaners into the disposal—chemicals can damage the unit and be hazardous when combined with metal fragments.
- Do not attempt high-force repairs (hammering or prying) without the right tools and experience.
When to Call a Professional
- The motor still hums but the plate won’t move after you’ve tested with the proper hex key.
- You see broken metal, stripped parts, or missing impellers inside the unit.
- The reset button keeps tripping or the unit trips the breaker repeatedly.
- Wiring or switch changes were recently made and the unit behaves abnormally.
Safety Notes
- Always disconnect power at the breaker or unplug before working on the disposal.
- Use eye protection and sturdy gloves when removing debris—sharp shards can be present.
- Use the correct Allen wrench provided by the manufacturer if your unit has a bottom access socket.
- If you are unsure about electrical work or internal damage, stop and call a licensed plumber or appliance technician.
Common Homeowner Questions
- Why does it hum but not turn? Usually a jammed impeller or an overloaded motor; power off and try the manual turn test.
- Can I turn the plate by hand? Not with your fingers—use the bottom hex key or a wooden tool and keep power off.
- Will the warranty cover a jammed disposal? It depends on the cause and the warranty terms; physical damage from foreign objects is often excluded.