How To Install A Garbage Disposal

Doing dishes isn’t anyone’s favorite chore. Do you often wonder if it would be quicker or easier with the help of a garbage disposal? After all, you don’t have to constantly empty out a sink drain screen to stop the sink from clogging up when you have a garbage disposal. There’s no reason why you need to waste time and water doing dishes when you have a garbage disposal to help. In this step-by-step guide, we teach you how to install a garbage disposal.

Keep reading to get all the tips and tricks to handle this DIY plumbing project.

Getting Started

Here’s a list of supplies and tools to get you started:



  • Hammer
  • Channel-Lock Pliers
  • Flathead Screwdriver
  • Phillips Screwdriver
  • Pipe Wrench
  • Wire Cutters

Step 1: Wire The Disposal

  • First, remove the disposal from the box and packaging.
  • To ensure you have all the right parts and materials, read the owner’s manual. Otherwise, you may run into trouble.
  • Then, note the wiring colors to prevent injury or damage.
  • Before wiring the disposal, be sure to cut the power off at the breaker. To be extra cautious, you can test the outlet with a multimeter.
  • Now, remove the metal base plate on the bottom of the disposal to access the inside.
  • When connecting cords, connect white to white, black to black, and the green wire to the ground screw.

Step 2: Insert The Drain Flange

So, most garbage disposals need a new flange before installation. The drain flange is a metal disk on top of the drain on the underside of the sink. Attached to the flange is the drainpipe that goes down where the drain attaches.

  • First, roll a coil of plumber’s putty and put it on the bottom of the flange.
  • Take the flange and press it down with even pressure into the drain hole.
  • To prevent the flange from moving while you install the disposal, place something heavy on top of it.

Step 3: Install The Mounting Ring

To install the mounting ring, line up the rubber gasket between the bottom of your new flange and the ring. Tighten the screws for the upper ring. Be careful, though! Make sure you tighten the screws the same amount to ensure the ring is evenly secured around the gasket to create a watertight seal.

Step 4: Attach The Disposal

  • Set the disposal on a few books, a block of wood, or something sturdy while attaching.
  • Pay attention to the garbage disposal’s outlet and be sure it faces the drainpipe.
  • Grab the lower ring and turn it clockwise until the disposal is being held up by the mounting ring.
  • Stick a screwdriver into the bracket on the lower ring, and turn it clockwise until the disposal locks.

Step 5: Connect The Garbage Disposal To The P-Trap

  • If the discharge tube is too long, cut the pipe with pipe cutters.
  • Attach the drainpipe to the disposal outlet with pipe connections.

Step 6: Tighten Everything

  • Now, tighten all fasteners and all connections.
  • Then, plug up the sink and fill it with water.
  • Lastly, let the water drain and run the disposal to check for leaks.

Need Help With Something Else?

Finally, your disposal is all hooked up! Need something else done? At Drain Express, we’re plumbing and drain cleaning experts. We can help you with any plumbing issues, maintenance, or installation.

Give us a call today.