Plumbing: Installing a Garbage Disposer (Disposal)

A garbage disposer can be a great convenience but shouldn’t be used as a trash can. Overloading can lead to frequent drain clogs and , if you have a septic sys tem, can clog and ruin the leach field. Many kitchen drains function perfectly well with no disposer at all. As you install your disposer, keep these factors in mind:

Mounting assembly. Disposers are held in place by a mounting assembly that takes the place of a strainer basket in the sink. This mounting assembly is installed separately from the disposer. Setscrews tighten the assembly by pushing against a setscrew plate, pushing the mounting ring against a split ring to pull the flange tight against the sink.

Drain systems. The disposer discharge opening must be at least 3 in. (8 cm) above the drain stub-out in the wall for proper drainage. A disposer-replacement project is also a good time to replace and simplify the sink drain. A single P-trap system, shown below, works well and often frees up valuable space. Just make sure the tee fitting has an internal baffle to help prevent discharge backup into the other sink bowl.

Electrical requirements. Make sure your disposer is on a dedicated circuit not shared with any other outlets or light fixtures. If the disposer is hardwired rather than plugged in, the electrical cable or wires should be protected by flexible-metal conduit. If the old disposer has a plug-in cord in good shape, save it for use with the new disposer.

What’s included. The new disposer will include detailed installation instructions and a new mounting assembly and stopper. Use the new assembly because the old one may not precisely fit the new disposer. Most new disposers will not include an electrical cord or the straight discharge tube shown below.

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1. Shut off power. Disconnect disposer drain and dishwasher drain hose. Use blocks and shim to slightly wedge up disposer for easier removal. Lightly hammer on mounting ring lug to knock ring loose. Remove disposer.

2. Follow manufacturer’s wiring instructions to install electrical cord. On a flat, three-wire cord, ground is in the center, positive has smooth sheathing and neutral has raised ridges or indentations on sheathing.

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Home Maintenance for Dummies

Book Description:

Having a house can be a hassle. But thanks to timesaving, trouble-preventing strategies from these nationally recognized experts, now anyone can keep his or her palace in regal repair and have plenty of time left over for the fox hunts. This friendly book covers everything from plumbing to painting, with handy calendars to ensure nothing falls through the cracks -- including the cracks!

From the Publisher
In Home Maintenance For Dummies, readers will find out how to prevent costly repairs and safety hazards with handy calendars and checklists that will ensure nothing falls through the cracks -- including the cracks! Home Maintenance For Dummies covers everything from plumbing to painting with special tips on preparing for freezing winter conditions and sizzling summer days.

From the Back Cover
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The book is well organized and has two main sections, indoor maintenance and outdoor maintenance. The book also includes nice graphical guides for those of us (me!) that need more than your basic instructions. Another great feature of the book are montly to-do's, to keep you on track throughout the year.

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Some examples:
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3. Knock out plug inside dishwasher hose inlet, if necessary. Wedge new disposer in place and partially tighten lugs.

4. Attach tailpiece and drain tee. Slope the discharge tube slightly toward the drain. Mark and cut the discharge tube to length. Slide retaining ring and gasket over discharge and secure to disposer and drain tee. Tighten mounting ring.

Last modified: Friday, 2007-11-02 23:40 PST