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Assemble and Install New Drain Pipes — Connect the Discharge and Drain Pipes

Beginner

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How to Install a Garbage Disposal for the First Time · Step 6 of 7

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With the new strainer installed, assemble the new drain pipes. Use a hacksaw to cut the existing ABS drain pipe to the correct length. Dry-fit all new components, including the new tailpiece, P-trap, dishwasher wye, and connecting pipes. Once you confirm the fit, apply ABS cement to the pipe and fitting and press them firmly together, holding for a few seconds. Complete all connections to create the new drain system and reconnect the dishwasher hose to the wye fitting.

Goal: Build the new under-sink drain system

Used in this video

  • HacksawCutting ABS drain pipes to the required length
  • Tape MeasureMeasuring pipe lengths for accurate cuts
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FAQs

What are the essential safety steps to take before and during a first-time garbage disposal installation?

Always turn off the power to the sink area at the circuit breaker first to prevent electrical shock. Wear safety glasses to protect your eyes from debris, and use a bucket and rags to manage water spills. Ensure all electrical connections are secure and properly grounded before restoring power.

Beyond the disposal unit itself, what critical tools and materials are often overlooked but necessary for a smooth installation?

Don't forget plumber's putty for sealing the sink flange, a large bucket and plenty of rags (like HDX Microfiber Rags or WYPALL Towels) for catching residual water, and a good flashlight (like the Panther Vision FLATEYE) to illuminate the workspace. While not always included, you may need a specific InSinkErator 3 ft. Power Cord Installation Kit if your unit isn't pre-wired.

How much time should a beginner set aside for this project, and which part is typically the most challenging?

A first-time garbage disposal installation typically takes 2-4 hours, assuming no major plumbing issues. The most challenging parts are often securing the mounting assembly tightly to the sink to prevent leaks, and making proper, safe electrical connections if you're wiring it yourself rather than just plugging it in.

What are the most common mistakes first-time installers make, and how can I avoid them, especially regarding leaks?

Common mistakes include not applying enough plumber's putty around the sink flange, forgetting to remove the dishwasher knockout plug (if connecting a dishwasher), or not tightening the mounting bolts evenly. To avoid leaks, ensure all connections are hand-tightened and then carefully finished with pliers, and always double-check by running water through the sink for several minutes before buttoning everything up.

Assemble and Install New Drain Pipes — How to Install a Garbage Disposal for the First Time (Step 6, Video 2) | Stesso