Sink Disposal Troubleshooting (Troubleshooting Guide)

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Quick answer
Confirm the symptom
Tools and prep
Step-by-step troubleshooting
Common causes table
Parts matching
When to call a pro
FAQ
Related guides

Quick answer

If your sink disposal isn't working, first ensure it's plugged in and the reset button isn't tripped. Check for clogs or jammed objects. If it's humming but not spinning, it might be jammed. Always turn off the power before attempting repairs.

Confirm the symptom

Disposal won't turn on
Disposal hums but won't spin
Water drains slowly or not at all
Unusual noises when disposal is running
Leaks under the sink

Tools and prep

Screwdriver (flathead and Phillips)
Pliers
Hex wrench (usually included with disposal)
Flashlight
Bucket and towels (for cleanup)
Turn off power to the disposal at the circuit breaker
Shut off water supply if necessary

Step-by-step troubleshooting

Check Power and Reset
Do: Ensure the disposal is plugged in and the outlet is working. Locate the reset button on the bottom of the disposal and press it.
Observe: If the reset button pops back out, there's still a problem.
Means: The disposal should hum or turn on.
Next: Check for clogs or jams.
Check for Clogs or Jams
Do: Use a flashlight to look down the disposal. Use pliers or a hex wrench to manually turn the disposal's grinding plate.
Observe: Look for any foreign objects or debris.
Means: The disposal should turn freely if not jammed.
Next: Run water and test the disposal.
Run Water and Test
Do: Turn on the cold water and run the disposal. Use the reset button if needed.
Observe: Check if the disposal runs smoothly and water drains properly.
Means: The disposal should be working normally.
Next: If still not working, check for leaks.
Check for Leaks
Do: Inspect under the sink for any water leaks. Tighten connections if necessary.
Observe: Look for any wet spots or dripping water.
Means: The area should be dry with no leaks.
Next: If leaks persist, check the disposal's seals.
Inspect Disposal Seals
Do: Remove the disposal from under the sink and inspect the upper and lower seals.
Observe: Look for any cracks or damage.
Means: Seals should be intact and not damaged.
Next: Replace seals if necessary.
Replace Seals
Do: Purchase new seals and replace the damaged ones following the manufacturer's instructions.
Observe: Ensure seals are properly installed and secure.
Means: The disposal should be leak-free.
Next: Reinstall the disposal and test.
Reinstall and Test
Do: Reinstall the disposal under the sink and reconnect all plumbing.
Observe: Run water and test the disposal.
Means: The disposal should be working properly with no leaks.
Next: If issues persist, consult a professional.

Common causes

Cause	Likelihood	Difficulty	Part often needed
Overloaded Disposal Too much food or non-food items pushed through.	Common	Easy	None
Jammed Disposal Foreign objects or hard items like bones jam the blades.	Common	Easy–Medium	Hex wrench
Clogged Drain Food particles or debris block the drain pipe.	Sometimes	Easy–Medium	Plunger or drain snake
Worn Out Seals Seals deteriorate over time, causing leaks.	Sometimes	Medium	Upper and lower seals
Burnt Out Motor Overheating or overuse can burn out the motor.	Rare	Hard	New disposal unit
Faulty Switch The wall switch controlling the disposal may be faulty.	Rare	Easy–Medium	Wall switch

Parts matching

Ensure you have the right parts before starting repairs. Most disposals come with a hex wrench for manual turning.

Hex wrench (usually included)
Upper and lower seals
Wall switch
Plunger or drain snake
New disposal unit (if motor is burnt out)

Always double-check the model number of your disposal to ensure compatibility with replacement parts.

When to call a professional

If the disposal is leaking and you can't find the source
If the motor is burnt out and you're not comfortable replacing the unit
If you encounter electrical issues beyond the reset button
If the disposal is making unusual noises and you can't identify the cause
If you're not comfortable performing any of the steps yourself
If the disposal is old and frequently malfunctions
If there are signs of significant damage to the unit

FAQ

Can I put anything down the disposal?

No, avoid putting non-food items, fibrous foods, and hard items like bones down the disposal. Stick to soft food scraps.

Why does my disposal smell bad?

Bad odors usually come from food particles stuck in the disposal. Run cold water and grind ice cubes or citrus peels to freshen it up.

How often should I clean my disposal?

Clean your disposal monthly to prevent buildup and odors. Use ice cubes, citrus peels, or a disposal cleaner.

What should I do if my disposal is leaking?

First, identify the source of the leak. It could be from the seals, connections, or the disposal itself. Tighten connections or replace seals if necessary.