How to Install a Garbage Disposal Yourself: A Step-by-Step Guide

Thinking about replacing your garbage disposal on your own? You’ve come to the right place. Whether you’re upgrading to a more powerful model or replacing a broken unit, this DIY guide on how to install a garbage disposal yourself will walk you through every step of the installation process—no professional plumber required.

What You’ll Need

Before you begin, make sure you have the following:

• A new garbage disposal unit
• Plumber’s putty
• Screwdrivers (flathead and Phillips)
• Adjustable wrench
• Bucket or towel
• Optional: Dishwasher connector kit or extended sink flange (if applicable

Step 1: Turn Off the Power

Safety first! Head to your circuit breaker and shut off the power to your kitchen. This is essential before handling any electrical components.

Pro Tip: If space allows, remove the cabinet doors under your sink. It’ll give you much more room to work.

Step 2: Check Compatibility & Prepare Additional Parts

Dishwasher Connection: If you’re connecting a dishwasher, ensure the outlet hose is 7/8″ in diameter. If not, grab a dishwasher connector kit.

Sink Thickness: If your sink drain is thicker than ½”, you’ll need an extended sink flange to ensure a snug fit.

Step 3: Remove the Existing Mount (If Needed)

If you already have a three-bolt mounting system, you can reuse it. Otherwise:

1. Detach the mounting assembly from your old unit.
2. Loosen the three screws on the mounting ring and rotate it off.
3. Use a flathead screwdriver to pry off the retainer ring from the sink flange.
4. Remove the mounting ring, backup flange, and fiber gasket, then clean the area around the sink drain.

Step 4: Install the New Sink Flange

1. Apply a generous bead of plumber’s putty around the underside of the sink flange.
2. Press it into the sink drain opening firmly and evenly.
3. Avoid moving the flange once it’s seated to maintain a watertight seal.

Step 5: Assemble the Mounting System

Locate the rubber discharge outlet that came with your disposal.

Attach it using the provided metal bracket.

Insert the discharge elbow into the outlet coupling and secure it with the spring clamp.

Step 6: Prep for the Dishwasher (If Needed)

If connecting to a dishwasher, don’t forget to remove the plug from the dishwasher inlet on the disposal unit.

Connect the dishwasher hose and clamp it securely.

Step 7: Mount the Disposal Unit

1. Align the tabs on the disposal’s lower ring with the ramps on the mounting ring.
2. Twist it into place until it’s seated securely. A flathead screwdriver can help if it’s tight.

Step 8: Set Up the Drain Line

You can either reuse your existing P-trap or install new plumbing. Before starting, lay a drop cloth or towel under the sink to protect your cabinets.

Secure everything in place using coupling nuts.

Dry Fit the Parts: A typical P-trap includes a male threaded adapter, wall tube, and J-bend.

Once you’re satisfied with the fit, use two-part primer and PVC cement to secure the adapter. Let it dry for 15 minutes.

Insert the wall tube into the drain and connect it to the J-bend.

Step 9: Final Touches

Plug in the disposal and secure the power cable to keep it off the cabinet floor.

If your model includes a magnetic metal guard, install it around the disposal’s throat.

Remove any excess plumber’s putty from around the sink flange.

Install the splash guard into the flange opening.

You Did It!

Congratulations—your new garbage disposal is installed and ready to use! 🎉

Replacing your garbage disposal doesn’t have to be intimidating. Whether you’re upgrading to a better model or swapping out a broken unit, now you know exactly how to install a garbage disposal yourself—no need to call in a pro. With the right tools, a little patience, and this step-by-step guide, you’ve got everything you need to get the job done right.