Installing A Garbage Disposer

A garbage disposer requires an electrical source for power. If you don’t have one under the sink, you’ll need to install one. Check with local codes before installation. Some communities have codes that don’t allow disposers due to limits on sewer capacity. They may also require an air gap for a disposer and a dishwasher. If you have a septic system, install a disposer specifically designed for use with a septic tank. Too much food waste can interfere with the normal decomposition of septic waste.

HOW MUCH HORSEPOWER? In-home disposers with motors less than 1/2 horsepower are not recommended for households with more than two people. A 1-horsepower disposer is better. Not only is it more powerful, it has better sound insulation and may run more quietly.

If the sink is made of cultured marble or a composite, use silicone caulk instead of plumber's putty to seal the flange.

MATERIALS: Garbage disposer, electrical cord, plumber’s putty or silicone caulk

TOOLS: Screwdriver or disposer wrench, hacksaw or tubing cutter, water-pump pliers

SAVE THAT BRACKET - Are you replacing an existing garbage disposer with the same brand? You may be able to use the existing mounting bracket to make the job easier and quicker.

1 WIRE THE DISPOSER. The disposer may come with the appliance cord attached. If not, you will have to connect one. Remove the cover plate beneath the disposer. Most cords and disposers have the same colored wires. Connect white to white, black to black, and the green wire to the disposer's ground screw. If the colors are different, read the manufacturer's instructions for wiring.

2 APPLY PLUMBER’S PUTTY. Press a rope of plumber's putty onto the underside of the drain flange. Insert the flange into the drain hole and press down evenly. Install the backup ring, fiber gasket, and mounting ring from beneath the sink.

3 INSTALL THE MOUNTING RING. Tighten the mounting screws for the upper mounting ring. Alternate the tightening of the screws to pull the ring up evenly against the sink.

4 MOUNT THE DISPOSER. Place the disposer into the mounting ring, making sure the outlet of the disposer is facing the drainpipe connection. Turn the lower ring clockwise until the disposer is supported by the mounting assembly.

5 CONNECT THE OUTLET TO THE P-TRAP. Measure and then use a hacksaw or tubing cutter to cut the discharge pipe to length. Install the discharge pipe to the outlet of the disposer. Attach to the drain line with slip nuts.

6 TIGHTEN THE MOUNTING LUG. Insert a screwdriver or disposer wrench into the mounting lug on the lower mounting ring. Turn clockwise until the disposer is locked into place. Tighten all slip nuts snug using water-pump pliers. Run water into the sink. Turn on the disposer and check for leaks. Tighten fittings if necessary.

CONNECT A DISHWASHER - Be sure the disposer you purchase has a knockout for a dishwasher. Remove the knockout for the dishwasher connection on the disposer. Connect the dishwasher discharge line to the disposer using hose clamps. If local codes require an air gap between the dishwasher and the disposer, for instructions on installing one.

GETTING SOME LEVERAGE - Sometimes the trickiest part of mounting the garbage disposer is the moment when you lift it up and lock it into the mounting rings. The pros will stack a couple of thick telephone books under the unit so they won't have so far to lift. You can do the same thing, or use scrap lumber, a toolbox, or the box the unit came in.

Some disposers come with a special wrench that is used to turn the impeller when the disposer gets jammed. Keep it and the manual in an easy-to-remember location.

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