Waste-disposal unit
Adjustable wrench
Flathead screwdriver
Phillips screwdriver
Pliers
Plastic wire connectors
Plumber's putty
Romex cable
Receptacle box
Receptacle switch
120-volt receptacle
20-amp circuit breaker to a dedicated line
Installing a waste-disposal unit will make your kitchen more convenient. If you are planning a kitchen remodel, it makes sense to include this contemporary appliance, as it will also increase the value of your kitchen--and house. If you already have a disposal unit, you may want to consider replacing it with a newer, more energy-efficient model that will cut maintenance and operating costs.
1.
Preliminary Electrical Work
If you're installing a new unit rather than replacing an existing unit, you will need to install a box for the switch and receptacle. The switch, which will be connected to the disposal unit, should be placed above the kitchen counter near the sink. To install a new box, run a 12/2 Romex cable down the wall. The cable will need to run behind the drywall next to a stud. It connects the disposal unit to the switch and receptacle (Figs. 1 and 2). If you're replacing your disposal unit, you can use your current switch and receptacle box.
2.
Install the Sleeve
Lay a generous bead of plumber's putty on the underside of the sink flange. Slip the sleeve of the disposal unit into the sink drain, pressing firmly on the sink flange to make sure it's secure against the sleeve. (Fig. 3)
3.
Install the Assembly
This is done by first sliding the fiber gasket and metal mounting ring over the sleeve in the sink. Then push the gasket and mounting ring up to cover the sink flange. Place the backup ring over the sink sleeve, push it firmly up to the mounting ring, and pop the snap ring into the groove of the sleeve. Be sure the mounting assembly is seated firmly and evenly before tightening the assembly screws. (Fig. 4)
4.
Wire the Disposal
Remove the electrical cover plate from the unit to expose the wiring. Connect the white wire (neutral) of the appliance cord to the white wire on the disposal unit, and do the same with the black (hot) wires, connecting black wire to black. Twist wire connectors over the connections to cover the bare wires. Screw the green (ground) wire on the appliance cord to the disposal unit (Fig. 5). Put the electrical cover plate back into place.
5.
Attach the Disposal
If the disposal unit is being installed in conjunction with a dishwasher, make sure the dishwasher nipple on the disposal unit faces the dishwasher, and remove the drain plug from the nipple. If you do not have a dishwasher, this nipple must stay in place. Carefully lift the disposal unit into position, aligning it with the mounting screws on the sink assembly. Then turn the lower mounting ring on the disposal unit to the right, engaging the flanges on the upper mounting rings. (Fig. 6)
6.
Connect the Plumbing
For obvious reasons, this is a very important step if you want to keep your kitchen dry. Begin by screwing the discharge pipe into the lower part of the disposal unit and fastening it in place using the rubber gasket and metal flange. Then move the unit until it aligns with the P-trap portion of the discharge pipe. Slide the nut and washer of the drainpipe onto the discharge pipe, attach the P-trap, and use a wrench to tighten the slip nut. If you are using a dishwasher, secure the dishwasher's drain hose to the nipple of the disposal unit. (Fig. 7)
7.
Finishing Tasks
Turn a screwdriver, inserted into a mounting lug, counterclockwise until the disposal unit is fully engaged in the locking notch (Fig. 8). Slowly run cold water into the sink and turn on the unit. Look closely at the drain connectors to make sure they are free of leaks. Your waste-disposal unit is ready for its first job!
