How to install a garbage disposal

We'll install the garbage disposal from flange to drain—electrical and plumbing.

What you'll need

At a glance

Mount the sink flange with plumber putty from above; secure the mounting ring from below.
Connect the disposal to the mounting assembly and twist to lock it in place.
Attach the drain hose and dishwasher inlet if you have a dishwasher.
Wire the disposal to the electrical box—if you are not comfortable with wiring, call an electrician.
Connect the drain pipe to the disposal and the P-trap; check for leaks before use.

Quick triage — pick your path

Choose the option that matches what you see. You can jump straight to that section.

Goal: Install the garbage disposal from flange to drain.

Goal: Seat the sink flange so the disposal can mount.

Apply plumber’s putty around the flange. Insert from above. Secure the mounting ring from below.
Good: Flange is snug. Proceed to Mount the disposal.
Bad: Putty oozes excessively—remove and use a thinner bead.

Goal: Lock the disposal to the flange.

Goal: Attach the dishwasher hose (if present) and the drain pipe.

Connect the dishwasher hose to the disposal inlet. Attach the drain elbow and pipe to the P-trap.
Good: All connections tight. Proceed to Wire and test.
Bad: Drain does not align—adjust the P-trap or use an extension.

Goal: Connect power and verify no leaks.

Wire the disposal to the electrical box (or have an electrician do it). Turn on the circuit breaker.
Run cold water and test the disposal. Check for leaks.
Good: No leaks; disposal runs smoothly. Proceed to Verification.
Bad: Leak at flange—tighten the mounting screws. Leak at drain—check slip nuts.

Call a plumber or electrician if:

Reviewed by Blackbox Atlas

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