Garbarge Disposal

New garbage disposals offer many new features, including quieter operation, increased grind capacity, and easier installation. When it is time to replace a garbage disposal, follow these step-by-step instructions that will help remove an old disposer and install a new garbage disposer.

To begin, turn off power to the garbage disposer at the electrical box. If your disposer plugs into the wall, unplug it. Shut off the water lines to the sink. Before dismantling the old disposer and plumbing, take a photo of the old setup for reference in installing the new unit.

Place a bucket or basin under the disposer and adjacent plumbing to catch any water. Identify the discharge tube that leads off of the disposer and disconnect it. Disconnect the dishwasher drain, if applicable.

Identify the mounting collar that holds the top of the garbage disposer to the bottom of the sink. Loosen and remove the mounting collar with a disposer wrench, which is typically included with your unit. If the garbage disposer is hard-wired, lay the unit on its side and locate the electrical cover plate. Disconnect the wires, and then remove the unit.

Inspect all parts that attach the garbage disposer to the sink. If in good condition, the replacement unit may be installed using these parts. If not, first loosen the mounting screws. Then, pry the snap ring out to release the mounting ring. Use a flathead screwdriver to pry off the backup flange and gasket. Remove the sink flange from above the sink. Clean the entire area of old putty and grime.

If you are replacing the sink flange, first apply a 1/2 inch-wide bead of plumber’s putty around the rim of the new flange. Press the new flange into position in the sink. To protect your sink and hold the new flange in position, place a towel over the new flange, then set the new disposer or other weight on top.

To begin installing the new hardware, first stack the mounting ring (screw heads down), backup flange, and gasket. Under the sink, place them over the sink flange outlet. Attach the snap ring to hold them in place. Tighten the mounting screws, alternately tightening each screw a few turns at a time until every screw is snug. Do not overtighten mounting screws.

If installing the garbage disposer to work with a dishwasher, refer to the manufacturer’s instructions for specific steps. Typically, this means tapping out the dishwasher knockout plug and attaching a line from the dishwasher to the disposer.

Reconnect either the hard wire or corded plug with wire connectors. Hang the unit by aligning the mounting rings. Reattach all the pipes, including the dishwasher. If any pipes are too long, cut them. Use extensions for any pipes that are too short.

Clean the excess putty off the sing flange. Install the baffle. Put a basin under the connections, turn the water on and test for leaks. Turn on the disposer and test again. To find detailed installation instructions, visit

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