Installing a Replacement Disposal

If you've just purchased a new InSinkErator disposal, you'll be glad to know our disposals are the easiest to install, remove, and replace.

Watch & Learn

InSinkErator shows you how to install a garbage disposal by following the steps outlined in the instructions manual and as shown in this 4-minute video.

Written Directions

Before attempting to install your disposal, read and understand the entire InSinkErator safety and installation instructions listed below.

Materials Needed

Plumber's Putty (.1 kg)
Wire Nuts (2-size 54)
Worm Gear Clamp
Dishwasher Drain Connector Kit (optional)
Channel-Lock Pliers
Flathead Screwdriver
Phillips Screwdriver
Pipe Wrench


Turn off power to the garbage disposal and disconnect the down trap.

Turn off the electrical power at the fuse box or circuit breaker. Then, using adjustable pliers, disconnect the drain top from the disposal waste discharge tube. (See Fig 1a)


Free the disposal from the mounting assembly.

Support the disposal with one hand and insert the end of the wrenchette or screwdriver into the right side of one mounting lug on the lower mounting ring. Lift the disposal slightly and loosen the lower mounting ring by pushing or pulling the wrenchette or screwdriver to the left until the disposal is free from the mounting assembly. (See Fig 1b)


Disconnect the electrical.

Lay the disposal on its side and remove the electrical cover plate from the bottom of the disposal. Loosen the green ground screw and remove wire connectors. Disconnect disposal wires from electrical supply wires. Loosen screws on the electrical clamp connector and remove wires from the disposal.


Remove existing mounting hardware if hardware replacement needed. Otherwise skip to step 12.

To remove the existing mounting hardware, loosen the three mounting screws, pry the snap ring off with a screwdriver and remove the old mounting assembly. (See Fig 2)


Remove the old sink flange and putty.

Push the old sink flange up through the sink hole. Use a screwdriver or putty knife to carefully scrape all old putty from the edge of the sink hole.


Install the new sink flange, gasket and rings.

Place a 1/2 inch rope of plumber's putty around the drain opening in the sink. Drop the new sink flange into the drain opening and press it into place. Placing a weight, such as a disposal, on top of the sink flange will help hold the sink flange in place while mounting the sink flange to the sink. To avoid scratching your sink or the flange, place a towel between the sink surface and the weight. (See Fig 4) From under the sink, slide the fiber gasket, backup flange and mounting flange over the sink flange. Hold these pieces in place.


Remove the dishwasher knockout plug.

If using a dishwasher, you will need to tap out the dishwasher knockout plug. Lay the disposal on its side and use a screwdriver and hammer to tap it out. Next, remove the loose knockout plug from inside the disposal. (See Fig 5)


Connect the electrical.

Lay the disposal on its side under the sink so you can make the electrical connections. Make sure the circuit breaker is off. Remove the plate on the bottom of the disposal to expose the wiring and use wire connectors to connect the wires from the disposal to the matching wires from the power supply. Finally, secure the power cord to the bottom of the disposal using the proper connection. Replace the plate to cover the wires. (See Fig 6)


Hang the disposal.

Hang the disposal by aligning the three mounting tabs with the slide-up ramps on the mounting ring. Holding the disposal in place, turn the lower mounting ring until all three tabs are locked into the mounting assembly. The disposal will now hang by itself.


Insert the discharge tube.

Insert the discharge tube into the discharge coupler, then slide the clamp over the discharge tube and position it in the groove on the rubber tailpipe coupler. (See Fig 7b)


Align the discharge tube with the drain trap.

Rotate the disposal so that the discharge tube is aligned with the drain trap. If the discharge tube is too long, cut off as much as necessary. If it is too short, you can purchase an extension.


Lock the disposal in place.

If you are connecting the disposal to a dishwasher, it may be connected through an air gap. Use a hose clamp to attach the drain hose to the dishwasher inlet. Now that everything is installed and in position, lock the disposal to the sink mounting assembly using the wrenchette that came with the unit. For Evolution models, insert the Quiet Collar® Sink Baffle into the sink opening by pressing it into the sink until it snaps into place. (See Fig 7c)


Test the disposal.

For all models, you should test for leaks at the sink flange, dishwasher, tail-pipe and mounting assembly connections. Finally, turn on the electrical breaker to test its operation.

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