Sink Disposal Installation

Turn off power to the garbage disposal and to the dishwasher at the breaker box.

Disconnect the down drain pipe from the P-trap and the sink using channel-lock pliers. Set the parts aside. Use the pliers also to disconnect the screw that holds the sink strainer in place on the sink. Set the strainer aside as well. Wipe away any plumber's putty that remains on the drain's opening.

Run a 1/2-inch bead of plumber's putty around the top of the sink's drain opening. Set the sink flange on top of the putty in the opening. Wipe off any excess putty that oozes onto the sink. Lay an old towel over the flange and then place a weight, such as a phone book, on top of it to hold it tight until the putty sets up.

Push the fiber gasket, backup flange and mounting flange onto the flange opening under the sink. Tighten the mounting flange. Slide on the mounting ring and tighten it. Do the same for the snap ring. Some models have screws that you tighten in addition to the rings. When you complete this step the bottom ring should be tight against the bottom of the sink.

Lay the sink disposal on its side with the dishwasher plug facing up. Put the slotted end of the screwdriver on the dishwasher plug. Tap the other end of the screwdriver with a hammer to knock out the plug. Remove the plug from inside the waste disposer. Skip this step if you aren't connecting the garbage disposal to a dishwasher.

Pop off the bottom plate of the garbage disposal to allow access to the wiring. Use the electrical cord hardwired by the electrician to the outlet, or use an appliance cord for garbage disposals that has an electrical plug on the opposite end. Thread the unwired end of the cord through the opening on the bottom of the garbage disposal. Wrap the ground wire, which is either green or bare, around the ground screw on the garbage disposal and tighten the screw with a screwdriver. Connect the black wire on the garbage disposal to the black wire on the cord with wire nuts. Do the same for the white wires. Put the bottom plate back on the disposal.

Locate the three mounting tabs on the garbage disposal. Match those three tabs with the three ramps on the mounting ring attached to the sink's drain. Twist the disposal counterclockwise until it locks into place.

Put the discharge tube into the discharge coupler on the disposer. Squeeze the clamp as you slide it into position to hold the discharge tube. Once the clamp is in the groove on the coupler, release it to hold the tube in place.

Align the discharge tube with the drain trap. Cut off excess tubing with a utility knife, if necessary. Attach the discharge tube to the drain trap with a locking collar and gasket. Tighten the collar with the pliers.

Use a hose clamp to connect the drain hose from the dishwasher to the garbage disposal unit. Tighten the hose clamp with a screwdriver. Skip this step if you aren't attaching a dishwasher.

Run water through the disposer to check for leaks. Tighten fittings if you see any seepage.

Plug the disposal unit into its outlet. Turn the power on at the breaker box. Run water through the disposer as you check its operation.