How To Plumb A Kitchen Sink With Disposal And Dishwasher

Have you ever thought of having a kitchen sink with disposal and dishwasher all integrated into your kitchen sink? To some, it sounds like something that is impossible to achieve, which is not.

Having a Garbage disposal and dishwasher are connected to your kitchen sink is important as it helps you to save time and energy, as you don’t have to be walking around to throw off the remnants from the dish.

However, the challenge most people face is how to install these two crucial features together or how to fix any form of leaks in the dishwasher or garbage disposal unit.

In this post, I will be showing safety tips on how to install a kitchen sink, whether it is the modern double basin sink with dishwasher and disposal that goes well for both right-handed people and left-handers or the traditional farmhouse-style stainless steel sink. In either of them, efficient plumbing is essential.

Why You Should Have A Garbage Disposal and Dishwasher?

Due to evolution and civilization, life is harder and more complex than before. As such we need new ways of making things easier for us.  So garbage disposal is one appliance you can’t do without in the kitchen as there will always be trash that needs to be disposed of.

Also, the dishwasher is an essential appliance that is developed to aid homeowners in simplifying kitchen tasks. With the dishwasher, you can have quick cycles and wash your plates without the help of anyone. Due to the fact that it consumes a lot of energy, you can settle for an energy-saving star-rated dishwasher.

So, with the best disposal by your side, you won’t have the problem of clogging and less food waste will end up in the trash. As such, you have directly reduced the rate at which rodents will attack your kitchen.

Having the dishwasher and disposal installed under a double kitchen sink in the home can help promote the overall hygienic nature of the kitchen.

Tools Required To Plumb a Kitchen Sink With a Garbage Disposal?

  • Pipe Cutter
  • Hex wrench
  • Screwdriver
  • Hacksaw
  • Hammer plies
  • Pipe Wrench
  • Cloth Piece


  • Cement
  • P-Traps
  • Dishwasher unit
  • Disposal unit

Step by Step Installation Process To Plumb a Kitchen Sink With a Garbage Disposal

Step 1: Familiarize Yourself With the Appliances

Before you begin installation one of the first steps is to familiarize yourself with all parts of the garbage disposal. Next, begin to assemble all the parts before you begin the installation so make sure they fit perfectly well.

Step 2: Begin the Installation Process

  • After assembling, the next step is to begin the installation. You can do it by yourself if you have plumbing knowledge. In the absence of that, you can hire a professional plumber.
  • In doing it yourself, first, apply a suitable plumber putty on the flange, then press it gently till it fits into place. Fix the disposal on the collar to prevent tightening it up.
  • Stack the fiber gasket, mounting ring, and backup flange gently into the underside of the collar. Once it is properly fixed, do ahead to install the snap ring. Ensure the screws are well tightened. Next, clean out the excess putty.
  • Next is to access the electrical cord by removing the wire cover plate. Matching the wire colors correctly to ensure it is done correctly. Once you are done, reattach the plate.
  • Next, remove the drain plug by using a hammer.
  • Connect the drain by gently inserting the gasket into the discharge outlet. Attach the discharge tube with bolts and flange. After you are done, hang the garbage disposal by aligning the three tabs to the mounting ring after which you can use the wrench to lock the tabs onto the ridges.

Step 3: Connect the Dishwasher drain

To connect the dishwasher drain, ensure that the discharge pile is aligned correctly. This should be properly checked before installing the drain pipes.

The process of connecting the dishwasher drain with the kitchen’ drainage is quite simple because the garbage disposal possesses an outlet that is designed uniquely for dishwashers. To install the dishwasher drain, you need some basic tools and they are:

What Are The Tools Required To Install a Dishwasher to a Garbage Disposal?

The Important Tools that you need to install a dishwasher to garbage disposal are:

  • Air gap fitting
  • Dishwasher install kit
  • Screwdriver
  • Light hammer
  • Utility knife
  • Two extra rubber compression washer
  • One inch hose clamp
  • Two compression clamps

Why is Installing a Dishwasher Drainage Important?

After your dishwasher is done washing the dishes, it drains the dirty water into the kitchen drainage system. Without having proper drainage, the dirty water can come up to dirty up the dishes again, which will be very disgusting. For your countertop dishwasher to function properly, an efficient drainage system is required to ensure the smooth flow of dirty water into the drainage system.

The Step by Step Installation Process

First Step: Turn Off the Water Supply

Before you begin the installation process, you need to turn off the water supply completely

Second Step: Disconnect the Garbage Disposal

Next is to disconnect the garbage disposal from the electrical outlet. In the case where the garbage disposal is permanently attached to the electrical circuit, what you have to do is to turn it completely from the main switch.

Third Step: Removing the Plugs

Next is to use a screwdriver and a light hammer to identify and remove the knockout plug inside the hose nozzle. To remove the plug from the nozzle, use needle-nose pliers.

Fourth Step: Fix The Essentialities

Insert gently a threaded stem located at the top of the air gap fitting into the hole situated at the back of the sink. Next, insert the runner washer located on the upper side of the stem, do tighten it up on the trim cap. To tighten the cap up, please avoid using pliers or wrenches. Instead, use your hands.

Using your hands, gently rotate the air gap fitting until the angled nozzle turns in the direction of the garbage disposal.

Gently, Push a side of the garbage disposal drain hose onto the nozzle on the dishwasher then tighten up the hose clamps situated on the other end of the hose. Next, Insert the lower clamp into the hose (at the nozzle) gently and then tighten it with up a screwdriver

Using a utility knife,  cut the upper side of the hose to a sizeable length. Ensure that it perfectly fits into the air gap nozzle perfectly without twisting.

Next, fix a one-inch hose clamp on the other side of the dishwasher drain hose. Do cut the hose to a sizeable length so that it can fit into perfectly the vertical nozzle without having to have a loop or bend it. Fix the end to the vertical; ensure you tighten it up with a hose clamp. And you are done!!

Frequently Asked Questions (FAQs)

Should the dishwasher be connected to the garbage disposal?

It is advisable you connect your dishwasher drain into the disposal to help simplify and make things easier for you in the kitchen. While washing the dishes on the dishwasher, you will need to dispose of the remnants of the food, and having garbage disposal connected helps to solve the problem. It helps to reduce the presence of trash in the kitchen capable of attracting insects like cockroaches or rodents.

Can a dishwasher drain directly into the waste line?

Yes, a dishwasher can drain directly into a waste pipe underneath the floor, but doing so has the tendencies of creating many potential problems.  Also, it is essential that the drain is connected to a proper fitting with a trap that helps to prevent the sewer gases from coming up towards the dishwasher.

Can I run my dishwasher drain to the sink?

Yes, it is very much possible, if your dishwasher and garbage disposal are correctly installed. But in the case where it is not properly installed, or one of them is damaged or broken, running both the dishwasher and the garbage disposal might become a problem.


Plumbing a kitchen sink with disposal and dishwasher is quite easy and possible. All you have to do is to follow the information listed above. Ensure to read the manufacturer’s instructions and carefully adhere to them before you begin the installation process

For further reading,  do check out “How to Prevent Falls in the Kitchen.”


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