Installing a disposer

Installing Your Replacement Disposer



Note: Important installation safety information is provided in the InSinkErator Disposer ICU manual. Before attempting to install an InSinkErator Disposer, first read and understand the entire safety and installation instructions. To download a free pdf version of the entire ICU manual and safety instructions click here.

If you´re shopping for an InSinkErator® food waste disposer or have just purchased one, you´ll be happy to know that InSinkErator® brand disposers are the easiest to install. That´s because all models feature our stainless steel QuickLock® sink mount. (And if you're replacing an InSinkErator® disposer, installation is even easier.) Just “twist off” the old disposer and “twist on” the new one. What's more, with QuickLock®, you can replace any disposer.

For your convenience, listed below are InSinkErator® installation instructions. Before attempting to install an InSinkErator Disposer, first read and understand the entire safety and installation instructions.


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Turn off the electrical power at the fuse box or circuit breaker. Using adjustable pliers, disconnect the drain trap from the disposer waste discharge tube. Support the disposer with one hand and insert the end of wrenchette or screwdriver into the right side of one mounting lug on the lower mounting ring. Continue to Step 2.
Lift the disposer slightly and loosen lower mounting ring by pushing or pulling wrenchette or screwdriver to left until disposer is free from mounting assembly. Continue to Step 3.
 Turn the disposer upside down and remove the electrical cover plate. Loosen the green ground screw and remove wire nuts. Disconnect disposer wires from electrical supply wires. Loosen screws on the electrical clamp connector and remove wires from disposer. For InSinkErator® model continue to Step 4a, all other brands continue to Step 4b.
Although you can use the same mounting hardware for your new InSinkErator disposer as you had with your old one, it's a good idea to make sure the mounting hardware is not rusted or otherwise in poor condition. Continue to Step 5. If your mounting hardware needs replacement, continue to Step 4b.
To remove the existing mounting hardware, loosen the three mounting screws, pry the snap ring off with a screwdriver (being careful not to mar the surface of the sink) and remove the old mounting assembly. Then push the old sink flange up through the sink hole. Use a screwdriver or putty knife to carefully scrap all old putty from the edge of the sink hole. Continue to Step 4c.
Place a 3/4 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 your disposer, 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. Continue to Step 4d.
From under the sink, slide the fiber gasket and backup ring onto the sleeve. Hold these pieces in place. Next slip on the mounting ring and snap ring. Tighten the three mounting screws. Alternately tightening each screw a few turns at a time until the mounting assembly is evenly and tightly seated against the bottom of the sink. Continue to Step 5.
If using a dishwasher, you will need to tap out the dishwasher knockout plug. Lay the disposer on its side and use a screwdriver and hammer to tap it out. Next, remove the loose knockout plug from inside the disposer. Continue to Step 6.
Lay the disposer 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 disposer to expose the wiring and use wire nuts to connect the wires from the disposer to the matching wires from the power supply. Finally, secure the power cord to the bottom of the disposer using the proper connection. Replace the plate to cover the wires. Continue to step 7.
Align the disposer with the three mounting tabs on the sink mounting assembly. Holding the disposer in place, turn the lower mounting ring until all three tabs are locked into the mounting assembly. The disposer will now hang by itself. Continue to Step 8.
To install, simply slide the metal flange over the discharge tube and insert the rubber gasket into the discharge outlet. Then, secure the metal flange and discharge tube to the disposer with two bolts or one bolt depending on model. Rotate the disposer so that the discharge tube is aligned with the drain trap. If the discharge tube is too long, cut off as much of the tube as necessary. If it is too short, you can purchase an extension. Continue to Step 9.
If you are connecting the disposer to a dishwasher, it must be connected through an air gap. Use a hose clamp to attach the drain hose to the dishwasher inlet. Continue to Step 10.
Now that everything is installed and in position, lock the disposer to the sink mounting assembly using the special wrench that came with the unit. 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.

Materials Needed

  • Copper wire
  • Plumber's putty (.1 kg)
  • Wire nuts (2-Size 54)
  • Worm gear clamp
  • Dishwasher drain connector kit - optional
  • On-off electrical switch
Tools Needed
  • Hammer
  • Channel-Locks
  • Flathead screwdriver
  • Phillips screwdriver
  • Pipe wrench

    To download a free pdf version of the entire ICU manual and safety instructions click here