Garbage Disposal Leaking

Diagnosing the leak location

Dry the entire disposal and the connections underneath the sink. Run water and watch closely for the first sign of moisture. The location tells you the cause:

• Water appears at the very top where the disposal meets the sink: Sink flange leak. The plumber's putty sealing the flange to the sink has dried and cracked.
• Water appears at a hose connection on the side: Either the dishwasher drain hose (small hose, upper side connection) or the discharge drain hose (larger hose, lower side). Check the clamps.
• Water drips from the very bottom of the unit: The internal seal around the motor shaft has failed. This is not repairable — the unit needs replacement.

Fixing a top leak: sink flange

1. From under the sink, loosen the three mounting tabs and rotate the disposal counterclockwise to lower it from the sink flange.
2. From inside the sink, pry up the flange and remove old putty.
3. Roll fresh plumber's putty into a rope, press it around the flange groove.
4. Re-seat the flange, reinstall the disposal, and tighten the mounting tabs evenly.
5. Wipe away excess putty that squeezes out from inside the sink.

Fixing a side leak: hose connections

Dishwasher drain hose: The small hose connecting your dishwasher to the disposal inlet. Tighten the hose clamp. If the hose is cracked, replace it ($5-10).

Discharge drain hose: The larger hose going from the disposal outlet down to the drain trap. Tighten the slip joint or hose clamp. If the rubber gasket inside the discharge elbow is cracked, replace it ($5-8).

Bottom leak: replace the unit

A bottom leak means the motor's internal seals have failed, allowing water from the grinding chamber to enter the motor housing. This is not a serviceable repair — the cost of parts and the difficulty of access make unit replacement the only practical option. A new disposal costs $80-200 and typically takes 30-45 minutes to install using the existing mounting assembly.

Frequently asked questions

My disposal leaks only when the dishwasher runs. What's the cause?

This isolates the leak to the dishwasher drain connection on the side of the disposal. The hose clamp has loosened or the rubber grommet at the inlet is cracked. Tighten the clamp first — if the connection is dry when only running water in the sink, the clamp is the fix.

How long do garbage disposals last?

8-15 years is typical. InSinkErator and Moen models tend to be at the longer end. Budget disposals often fail at 5-7 years. A bottom leak on a unit over 10 years old is a reasonable replacement trigger.

Can I use plumber's putty on a granite or composite sink?

Some composite sinks advise against plumber's putty because it can stain — use silicone instead. Check the sink manufacturer's recommendation. For stainless steel and porcelain, plumber's putty is standard.

Related guides

• Garbage Disposal Humming Not Spinning
• Dishwasher Not Draining
• Refrigerator Leaking Water

Last updated June 2, 2026. Repair procedures and part prices verified against manufacturer documentation and current market pricing. Confirm prices at time of purchase.