Symptoms: Leaking

Garbage Disposal Leaking? Find the Source Before You Call a Pro

Where the water appears, at the sink flange, the dishwasher hose, or the bottom of the unit, tells you almost everything before you open the cabinet.

Risk: Low
Difficulty: Beginner
Estimated time: 15 to 40 minutes

Before you start

Unplug the appliance, shut off the water supply if relevant, and stop immediately if you smell burning. If in doubt, call a qualified professional.

On this page

Tools needed
Probable causes
First checks
Step-by-step diagnosis
Mistakes to avoid
When to stop
Parts involved
When to call a professional

A leaking garbage disposal has one of a few likely sources, and where the water shows up narrows it down fast. Most leaks come from a connection point (the sink mount, the dishwasher hose, or the drain outlet), all of which are cheap, quick repairs. A leak from the bottom or side seam of the unit itself is the one exception, and it means the case has failed internally, which calls for replacement, not repair.

This page is part of our full garbage disposal troubleshooting guide.

Quick Diagnosis Table

Leak Location	Likelihood	Difficulty	Typical Part Cost
Sink flange / mounting gasket (top of unit, under the sink strainer)	Very likely	Easy to moderate	$10–20
Dishwasher connection hose or clamp	Likely	Easy	$5–10
Discharge drainpipe gasket (unit to P-trap)	Likely	Moderate	$5–15
Reset button seal or side seam (cracked housing)	Possible	Not repairable	Replace unit, $100–250
Internal seal failure, leaking from the bottom of the case	Possible	Not repairable	Replace unit, $100–250

How to Find the Source

Dry the entire underside of the unit and the cabinet floor with a towel, then run water into the sink without turning the disposal on. Watch the top mounting ring first: water beading there means the flange gasket has failed. Next, run the dishwasher briefly (or just its drain cycle) and check the dishwasher hose connection on the side of the unit. Finally, run water again and check the discharge pipe connection at the bottom where it meets the P-trap. If none of those are wet but the bottom of the metal case itself is damp, the leak is internal and the unit needs replacing.

Repair or Replace?

A flange gasket, dishwasher hose, or discharge pipe gasket is a cheap, straightforward swap that takes most people under 30 minutes with basic tools. A leak from the case itself, whether at the reset button, a side seam, or the bottom, means the internal seal around the motor has failed, and that’s not something home repair kits address. At that point, replacing the unit is the only real option.

See our InSinkErator and Badger guides for brand-specific mounting hardware notes.

Frequently Asked Questions

The information provided here is a diagnostic aid and does not replace the intervention of a qualified professional.

Tools needed

Towel
Adjustable wrench or pliers
Plumber's putty (if flange is the source)
Replacement gasket or hose clamp as needed

Probable causes

Very likely Sink flange or mounting gasket
Likely Dishwasher connection hose or clamp
Likely Discharge drainpipe gasket
Possible Reset button seal or cracked side seam
Possible Internal seal failure at the bottom of the case

First checks

Dry the entire underside of the unit and cabinet floor with a towel before testing.
Run water into the sink without switching on the disposal and check the top mounting ring first.
Run the dishwasher's drain cycle and check the side hose connection.
Check the bottom discharge pipe connection to the P-trap.

Step-by-step diagnosis

Turn off the water supply and unplug the disposal before starting any repair.
For a flange leak, loosen the mounting ring, remove the old putty or gasket, and reseat with fresh plumber's putty or a new gasket.
For a dishwasher hose leak, tighten or replace the hose clamp at the connection point.
For a discharge pipe leak, tighten the slip nut or replace the gasket where the pipe meets the P-trap.
If the leak traces to the unit's case itself, plan to replace the disposal rather than attempting an internal repair.

Mistakes to avoid

Over-tightening plastic slip nuts, which can crack the fitting and create a worse leak.
Assuming any leak means a full replacement before actually isolating the source.

When to stop

The leak is coming from the case itself, not a connection: stop repair attempts and plan for replacement.
Water is pooling near any electrical connection: unplug the unit immediately and don't run water again until dry.

Parts potentially involved

When to call a professional

If the simple checks didn’t solve it, if the fix involves electrical wiring, gas, or the refrigerant circuit, or if you have any doubt at all: stop there and hand the appliance to a qualified repair professional.

Related guides

Error codes for this appliance

The information provided here is a diagnostic aid and does not replace the intervention of a qualified professional.

July 20, 2026

Sam Radford — DiagnosFix

Technical reviewer

Last verified: 2026-07-19