How to Hook up a Kitchen Sink Drain With a Garbage Disposal

Wiring

• 1

  Shut off the electricity to the kitchen. It's even safer to shut off the main.

• 2

  Select the location for your wall switch. The best location is close to the sink. Draw around the open side of the electrical box. The wires feed into the electrical box from inside the wall and the switch screws into the front. Cut out the wall for the wiring box. Use shallow cuts to avoid cutting wires in the wall.

• 3

  Make a cut in the wall below the sink. You will need a hole through which to feed the wiring for the disposal. If the disposal has a plug, draw around the electric box and cut out the wall to size. If you must wire the device, make a hole that allows you to work conveniently.

• 4

  Go to the outlet closest to your disposal unit. If you chose to shut off power to the kitchen only, use a voltage tester to ensure the electricity is off. If a voltage tester is unavailable, plug something in to ensure that electricity has been turned off. Remove the cover and examine the wires. There should be incoming and outgoing wiring.

• 5

  Remove a black wire from the receptacle terminal. Join it with a black wire from the switch and a jumper wire by twisting the bare ends together. A jumper wire is a short piece of wire that connects the main electrical wiring to the outlet's terminals. Tighten them together with a twist-on wire connector, also known as a wire nut. The connector fits onto the twisted ends then you twist it to lock it. Attach the jumper wire to the terminal.

• 6

  Remove a white wire from the receptacle terminal and join it with the white wire from the switch and a jumper wire. Use a wire stripper to remove the wire's cover if you need more bare wire. Twist the bare wire ends together. Attach the jumper wire to the terminal. Attach the wire nut as you did in Step 5.

• 7

  Attach the bare wire from the outlet to the one running to the switch plate. Bare wires ground the switch. There will be a green wire in the electric box. Attach the bare wires to the green wire and a green jumper wire. Twist them and tighten with the wire nut like you did in the other steps. Attach the green jumper wire to the switch in the same location as the old green wire.

• 8

  Feed your new wire to the wall switch box. It's easiest to use a straightened clothes hanger. Twist the wire onto the end of the clothes hanger and feed it through the wall to the new box.

• 9

  Split the wall switch's wires. Follow Steps 5 through 7 substituting "switch" for "outlet."

  Using the clothes hanger again, run the wires through the wall to the garbage disposal.

• 10

  Check the wire nuts to ensure they are tight. Wires attached to the switch should also be snug. The electrical box should be secure against the wall stud. Sit the switch in the box and screw on the faceplate.

Disposal Installation

• 11

  Shut off the water main. If you have a single family home, it is probably in your front yard near the street. If you rent an apartment, check with your landlord. Turn off the breaker to the hot water tank to avoid damage.

• 12

  Remove the cold water line from the faucet.

• 13

  Use a pipe wrench to disconnect the drain pipe from the sink.

• 14

  Unscrew the clips that attach the sink to the counter. Doing so makes it easier to assemble some of the garbage disposal's parts.

• 15

  Use a compression coupling to attach the water line to the disposal's water line. The water line is the one you removed from the faucet. There is only one line attached to the disposal. Slide the nut on to one of the lines then add the coupling. Attach the second line and tighten the coupling by hand.

• 16

  Remove the strainer body from the sink and insert the disposal's strainer in its place. Put plumber's putty under the lip of the new strainer.

• 17

  Slide on the rubber and metal gaskets.

• 18

  Loosely thread the mounting bolts before you snap on the support ring.

• 19

  Tighten the bolts on the support ring. Use caution to avoid buckling it.

• 20

  Using plumber's putty; put a bead of approximately 1/4 inch around the counter's top where the sink's lip sits. Re-mount the sink and screw the clips into place. Ideally, you should have about eight clips. Evenly space them to ensure the sink fits tightly on the counter.

• 21

  Lift the disposal unit until it locks into the strainer sleeve.

• 22

  Attach a 1.5 inch "P" trap to the disposal and the drain. Put Teflon tape around each end before connecting them.

• 23

  Install the disposal's wiring. Match the black, white and bare wires with the ones you fed from the switch. Twist them together and add wire nuts. If the disposal has a plug, install the wiring as an outlet by following Steps 5 through 7. Jumper wires are unnecessary.