How to Plumb a Double Sink With Garbage Disposal Plumbing

Double sinks are convenient and practical for any kitchen. However, plumbing a double sink with a garbage disposal can be a bit tricky, especially if you don’t have the right tools or experience. In this article, we’ll cover the step-by-step process of how to plumb a double sink with garbage disposal plumbing, as well as tips on how to unclog it when necessary. Additionally, we’ll discuss when it’s appropriate to call in a professional plumber.

How to Plumb a Double Sink with Garbage Disposal Plumbing

Before beginning the process, ensure that you have all the necessary tools and materials, including a new garbage disposal unit, sink strainer, plumber’s putty, PVC piping, and connectors.

Step 1: Turn off the water supply

Before doing any plumbing work, turn off the water supply to your kitchen sink. There should be a valve located underneath your sink or near your water heater. Turning off the water supply will prevent any water from flowing while you’re working on the pipes.

Step 2: Disconnect the old garbage disposal

If you’re replacing an old garbage disposal unit, you need to disconnect it first. Unplug the unit from the electrical outlet and disconnect the drain pipes from the disposal. Use a wrench to loosen the mounting bolts, and then remove the old unit.

Step 3: Install the sink strainer

Insert the sink strainer into the drain hole of your sink. Apply a small amount of plumber’s putty around the rim of the strainer to create a seal between the strainer and sink. Tighten the mounting nut underneath the sink to secure the strainer in place.

Step 4: Install the garbage disposal

Insert the new garbage disposal unit into the mounting assembly. Tighten the mounting bolts using a wrench. Connect the drain pipe to the disposal, and then connect the discharge pipe to the drainpipe.

Step 5: Install the tee assembly

Connect the tee assembly to the drainpipes coming from both sinks. The tee assembly connects the two drains and directs water flow to the garbage disposal.

Step 6: Install the P-trap

Attach the P-trap to the tee assembly. The P-trap is a U-shaped piece of PVC piping that traps debris and prevents it from entering the main sewer line. Tighten the slip nuts to secure the P-trap in place.

Step 7: Test the plumbing

Turn on the water supply and test the plumbing by running water through both sinks and the garbage disposal. Check for any leaks or strange noises. If everything looks and sounds good, your plumbing job is complete.

How to Unclog a Double Sink with Garbage Disposal Plumbing

Even with the best maintenance, double sinks with garbage disposals can get clogged. Here’s how you can unclog it:

Step 1: Turn off the garbage disposal

Turn off the garbage disposal unit to prevent it from causing any further damage.

Step 2: Plunge the sink

Place a plunger over the drain of the clogged sink and apply firm pressure. If you’re plunging one sink, cover the other sink’s drain with a stopper to create more suction. Repeat the process a few times, and then turn on the water to see if the clog has been cleared.

Step 3: Use a snake

If plunging doesn’t work, use a plumbing snake to remove the clog. Insert the snake into the drain and turn the handle clockwise until you feel resistance. Once you reach the clog, turn the handle counterclockwise to remove it.

Step 4: Try a drain cleaner

If plunging and using a snake don’t work, try using a drain cleaner. However, be careful when using a drain cleaner, as it contains harsh chemicals that can damage your pipes if used improperly. Follow the instructions on the package carefully, and wear protective gloves and eyewear.

When to Call a Professional

If you’ve tried all the DIY methods and still can’t eliminate the clog, it’s best to contact a professional plumber. They have the tools and expertise to diagnose the problem and fix it quickly and efficiently. Additionally, if you’re not comfortable with plumbing or don’t have the necessary tools and experience, it’s always best to call a professional. Attempting to fix the problem yourself can lead to further damage, resulting in costly repairs in the long run.


Plumbing a double sink with a garbage disposal can be a challenging task, but with the right tools and knowledge, you can do it yourself. The key to a successful plumbing job is to follow the steps carefully and take your time. Additionally, if you’re dealing with a clogged sink, try the DIY methods first before calling in a professional. Remember to turn off the water supply before doing any plumbing work, and always wear protective gear when using drain cleaners or handling pipes.

Overall, plumbing a double sink with garbage disposal plumbing requires a bit of expertise, but it can be done with the right tools and knowledge. When it comes to a clogged sink, try plunging, using a snake or drain cleaner before calling in a professional. And, always prioritize safety and turn off the water supply before attempting any plumbing work. By following these tips, you can ensure your kitchen sink stays functioning smoothly for years to come.

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