Garbage Disposal Leaking? Find the Source & Fix It

If you’ve found water under your sink or dripping from the garbage disposal, the first step is identifying where it’s coming from. The leak location determines whether this is a DIY fix or time for a new disposal.

This guide helps you pinpoint exactly where your disposal is leaking and provides step-by-step fixes for each type of leak.

Where Is It Leaking? (This Determines the Fix)

Leak Location	What It Means	Can You Fix It?
Top (sink flange)	Mounting loose or putty dried out	Yes — usually easy
Side (connections)	Dishwasher hose or drain pipe loose	Yes — usually easy
Bottom (unit itself)	Internal seal failure	Usually no — replace

To find the exact source:

Dry everything under the sink with paper towels
Plug the sink and fill it with a few inches of water
Unplug and watch where water appears as it drains
Use a flashlight to pinpoint the drip
Run the dishwasher cycle if connected — check that hose too

Video Guide

Video: “Leaking Garbage Disposal? Quick Fix Trick Revealed!” by Don Wynn

Understanding Disposal Leak Points

A garbage disposal has several potential leak points, each with different causes and fixes.

Sink flange (top): This is where the disposal connects to the sink drain. A metal ring sits in the drain opening, sealed with plumber’s putty and secured by a mounting assembly. Over time, putty dries out or bolts loosen.

Dishwasher connection (side): Many disposals have a nipple for connecting the dishwasher drain hose. A rubber hose attaches with a clamp. Leaks happen when the clamp loosens or the hose cracks.

Drain pipe connection (side): The discharge tube carries water from the disposal to the drain pipe. It connects with a rubber gasket and slip nut. Gaskets wear out, nuts loosen.

Body of the unit (bottom): Internal seals separate the motor housing from the grinding chamber. When these fail, water leaks from the bottom. This is usually the end of the disposal’s life.

How to Find the Exact Leak Source

If you’re not sure where the leak is coming from, follow these diagnostic steps:

Step 1: Dry Everything

Wipe down all parts of the disposal and pipes with paper towels. Remove any standing water from the cabinet floor.

Step 2: The Fill Test

Plug the drain (use a stopper or wet rag)
Fill the sink with 3-4 inches of water
Add a few drops of food coloring (makes leaks easier to spot)
Wait 10-15 minutes
Check under the sink for colored water

Where colored water appears:

Around the flange mounting = top leak
Running down the side of the disposal = side connection leak
Dripping from the body or bottom = internal leak

Step 3: The Drain Test

If no leak appeared while water sat in the sink, pull the stopper and watch as water drains:

Leaks that appear during draining but not while sitting = connection issue activated by water flow
Observe which connection water runs from

Step 4: The Dishwasher Test

If your dishwasher drains through the disposal:

Run a dishwasher cycle
Watch the dishwasher connection hose
Check for water at the clamp or hose

Step 5: Paper Towel Wrap

For stubborn leaks:

Wrap paper towels around each connection point
Run water through the disposal
Check which towel gets wet first

Fix: Leak from the Top (Sink Flange)

Leaks from the top are the most common and usually the easiest to fix. The sink flange is the metal ring where the disposal connects to the sink drain.

What causes it:

Mounting bolts loosened over time
Plumber’s putty dried out and cracked
Disposal shifted from vibration

Try This First: Tighten the Mounting Bolts

Look under the sink at the mounting ring that connects the disposal to the flange
Find the mounting bolts (usually 3)
Tighten each bolt a quarter turn at a time, alternating between them
Test by running water

Important: Tighten evenly. If you tighten one bolt fully before the others, you’ll create uneven pressure and the seal won’t hold.

If tightening doesn’t work, you’ll need to re-seat the flange.

Re-Seat the Flange

This is more involved but still a reasonable DIY project.

What you need:

Plumber’s putty
Screwdriver (flathead and Phillips)
Towels
Bucket

Steps:

Disconnect the disposal from the mounting assembly (usually a twist-off — turn counter-clockwise)
Loosen the mounting ring from below
Push the flange up from below until it pops out of the sink
Scrape off all old plumber’s putty from the sink opening and flange underside
Roll fresh plumber’s putty into a rope about 1/2” thick
Apply putty rope around the underside of the flange lip (where it will contact the sink)
Press flange back into the drain hole from above
Go back under the sink and reinstall the mounting ring
Tighten mounting bolts evenly, alternating between them
Wipe away excess putty that squeezes out above
Reattach the disposal
Test for leaks

Note: Use plumber’s putty, not silicone caulk. Putty stays workable if you ever need to remove the flange again. Silicone makes future repairs much harder.

Fix: Leak from the Side

Side leaks come from connections — either the dishwasher hose or the drain pipe.

Dishwasher Connection Leak

The dishwasher drain hose connects to a nipple on the side of the disposal.

To fix:

Check if the hose clamp is loose — tighten with a screwdriver
Inspect the hose for cracks — replace if damaged
Check the rubber gasket inside the connection — replace if worn
Make sure the hose isn’t kinked, which can cause pressure buildup

Hose clamp types:

Spring clamps: Squeeze with pliers to release, reposition, release
Worm-drive clamps: Tighten with a screwdriver
If the clamp is corroded, replace it

Replacing the hose:

Remove old clamp
Pull hose off nipple
Buy replacement hose (available at hardware stores)
Slide new hose onto nipple
Secure with new clamp

Drain Pipe Connection Leak

The drain pipe connects to the side of the disposal via a flange with a rubber gasket.

To fix:

Tighten the slip nut that holds the connection
If still leaking, remove the connection and check the rubber gasket
Replace the gasket if it’s worn, compressed, or cracked
Check the threads on the connection — wrap with plumber’s tape (Teflon tape) if worn
Reassemble and tighten

Gasket replacement:

Place bucket under connection
Loosen slip nut by turning counter-clockwise
Pull drain pipe away from disposal
Remove old gasket from the disposal flange
Install new gasket (beveled side faces into disposal)
Reattach pipe, tighten slip nut

Side leaks are almost always fixable with tightening or gasket replacement.

Leak from the Bottom — Time to Replace

A leak from the actual body of the disposal (not a connection) means the internal seals have failed.

Why this can’t be fixed:

The seals are built into the unit and aren’t user-replaceable
The housing may be corroded
Repair labor would exceed replacement cost
Opening the unit voids any warranty

Signs it’s an internal leak:

Water drips from the bottom center of the disposal body
Visible corrosion or rust on the housing
Unit is 8+ years old
Connections are all dry but there’s still water
Water appears even with disposal not running (sitting water in chamber draining through failed seal)

What to do:

Stop using the disposal to prevent water damage
Shop for a replacement — most units are $80-300
Consider professional installation ($150-200) or DIY if comfortable

Choosing a Replacement

When buying a new disposal:

Motor power: 1/2 HP for light use, 3/4 HP for average, 1 HP for heavy use
Stainless vs. galvanized: Stainless grind chambers last longer
Sound insulation: Higher-end models are quieter
Brand: InSinkErator and Waste King are the most reliable

DIY vs. Professional Installation

DIY installation is reasonable if:

You’re comfortable with basic plumbing
The new disposal uses the same mounting system as the old one
No electrical work is needed

Call a professional if:

You need electrical modifications (hardwiring, new outlet)
The mounting system is different
You’re not confident working under the sink
You want warranty protection on the installation

For other common problems, including issues that might accompany a leak, see our main troubleshooting guide.

Preventing Leaks

Keep your disposal connections healthy:

Regular checks: Every few months, look under the sink for moisture. Early detection prevents water damage.

Don’t overtighten: Over-tightening connections can crack plastic fittings or compress gaskets unevenly.

Avoid vibration damage: If your disposal vibrates excessively, something may be wrong. Vibration loosens connections over time.

Replace gaskets proactively: If you have the P-trap apart for other reasons, check the condition of gaskets and replace if questionable.

FAQ

Why is my garbage disposal leaking from the bottom?

Internal seals have failed. This usually means replacement, as the seals are built into the unit and aren’t user-serviceable. Bottom leaks are most common in disposals over 8 years old.

Can a leaking garbage disposal be fixed?

Depends on location. Top (flange) and side (connection) leaks are usually fixable by tightening or replacing gaskets. Bottom leaks from the unit itself typically require replacement.

How much does it cost to replace a garbage disposal?

$80-300 for the unit itself, depending on power and features. Professional installation adds $150-200. Handy homeowners can DIY the installation with YouTube guides.

Is a leaking garbage disposal dangerous?

Water damage can lead to mold and cabinet rot if ignored. Electrical components near standing water are also a concern. Fix or replace a leaking disposal promptly to avoid bigger problems.

Why is my garbage disposal leaking from the reset button?

Water from the reset button area indicates an internal seal failure. The reset button is on the motor housing, so water there has passed through the main seal. This means replacement.

Can I use silicone instead of plumber’s putty on the flange?

Plumber’s putty is preferred because it remains workable for future repairs. Silicone bonds permanently and makes future flange removal difficult. Use silicone only if specifically required (some stone sinks).