How to Replace Your Garbage Disposal

Reviewed by HomeMD.ai editorial team · Last updated: July 18, 2026

Understanding When to Replace Your Garbage Disposal

Garbage disposals usually fail from one of three common issues: a steady hum with no spin indicates a jam, loud grinding with leaks suggests worn internal seals, and a completely dead unit might have a tripped reset or burned motor. If your disposal is leaking from the bottom or is older than 8 to 12 years, it's time to consider replacement. This guide will show you how to replace a garbage disposal using the existing sink mount.

Tools and Materials Needed

Before you start, gather the necessary tools and materials. You'll need RIDGID tongue and groove pliers, a Klein Tools non-contact voltage tester, and a bucket. For materials, consider the InSinkErator Badger 5 1/2 HP Garbage Disposal, Everbilt Garbage Disposal Installation Kit, and Oatey plumber’s putty. You can find these items at your local hardware store or online.

Step-by-Step Guide to Replacing Your Garbage Disposal

Replacing a garbage disposal is a moderate DIY project that requires some experience. Follow these steps to ensure a smooth replacement process:

1. Cut power and water. Unplug the disposal or switch off the breaker. Confirm it is dead by ensuring you hear nothing when you flip the switch.
2. Disconnect plumbing. Loosen the slip nuts on the P-trap and dishwasher hose. Keep a bucket under it to catch any water. You will feel the trap drop once loose.
3. Remove the old unit. Support it with one hand and twist the mounting ring counterclockwise. It will drop suddenly when it unlocks.
4. Swap the mounting assembly if needed. Many new units include a new flange. Press plumber’s putty under the flange, tighten evenly until you see a thin bead squeeze out.
5. Wire the new disposal. Match black to black, white to white, green to ground. Tug gently to confirm tight connections.
6. Mount the new unit. Lift and twist until it locks. You will feel it “seat” when aligned correctly. If it sits crooked, it is not engaged.
7. Reconnect drain and dishwasher line. Knock out the dishwasher plug inside the inlet first if you have a dishwasher.
8. Test for leaks and run it. Restore power, run water, then turn it on. A healthy unit hums smoothly without rattling.

Cost Comparison: DIY vs. Professional Installation

Product Recommendations

For a reliable garbage disposal replacement, consider the InSinkErator Badger 5 1/2 HP Garbage Disposal. Pair it with the Everbilt Garbage Disposal Installation Kit and Oatey plumber’s putty for a complete setup.

FAQs

Why does my new disposal hum but not spin?
Likely a jam or the wrench slot needs turning to free it.

Do I have to replace the mounting ring?
Not always, but matching brands fit best and prevent leaks.

Can I reuse the old drain pipes?
Yes, if they line up and seals are intact. Brittle washers should be replaced.

What size disposal should I buy?
1/2 HP for light use, 3/4 HP for typical families, 1 HP for heavy use.

When handling plumbing tasks like replacing a garbage disposal, it's useful to have some knowledge of related systems such as toilets, water heaters, or pipes, as these can sometimes be interconnected in home plumbing systems.