How To Install A Dishwasher: All Steps Explained

Do it yourself videos and guides have been extremely helpful for people to lower the cost of fixing things and to get creative with their passion projects.

Almost everything nowadays can be DIY-ed and the same goes for installing a dishwasher. Whatever your kitchen situation may be, there are steps to help you install it yourself.

Can I Install A Dishwasher By Myself?

There are numerous situations in which a person would like to install a new dishwasher in their home but luckily, they’re not as different as a fingerprint of a person is, unique and unrepeatable. You can install it and if you just find out the circumstances under which you have to install it, you can easily do it on your own.

Is It Better To Just Call An Expert?

If you have at least some experience in these things, you don’t but if you realize that you don’t understand and don’t know how to perform the steps we’ll provide you with today, it’s best to call an expert.

Cost – Many people turn to do-it-yourself methods since installing a dishwasher can be expensive. For a plumber to install it you’ll pay anywhere between 500 dollars up to 3500 dollars (the more high-end the dishwasher, the more it costs) but you have to also include labor costs which can be anywhere from 250 dollars up to 500 dollars.


Check For These Things Before Attempting To Install

Is There An Existing Kitchen?

The easiest way to set up a dishwasher is in a brand new kitchen where there’s no countertop yet, no cabinets, and plumbing and wiring can be fixed to fit the location of the dishwasher. With a kitchen already there, you’re risking too much remodeling once you decide on a dishwasher and where you’re going to place it. You’ll have to install it in existing cabinets as well.

How Much Space Do You Have?

Dishwashers, as well as kitchens, come in standard sizes. As opposed to kitchens, dishwashers have what’s called a rough opening which means that their size is a bit smaller than what’s stated so that they can fit into kitchen cabinets.

Dishwasher Sizes(DxWxH)

  • Standard Dishwasher: 24” x 24” x 35”
  • Oversized Built-In Dishwasher: 24” x 30”- 42” x 35”
  • Compact Built-In Dishwasher: 24” x 18” x 35”

Notice how the only thing that ever really changes is the dishwasher width.

Standard Dishwasher Measurements
Kitchen Base Cabinet Sizing

  • Height, No Countertop: 34.5”
  • Height, Countertop: 35” – 36”
  • Depth, No Countertop: 24”
  • Depth, Countertop: 25”- 26”
  • Cabinet Width: 12”, 18”, 24”, 30”, 33”, 36”, 48”


There are three lines of connections to be made in dishwasher installation that make it a slightly more complicated job, it’s the power connection, drain, and water line connection

Where’s The Water Supply And Drain Line?
The more away from the sink, you decide to install your dishwasher, the more work you’ll have to do if it’s an existing kitchen. Both are usually located under the sink, so you suggest installing the dishwasher in either one cabinet to the right or the left of the sink.

Electric Plug

How Will You Power The Dishwasher?
If you don’t have experience in electrical wiring, you may run into some trouble trying to power the dishwasher. The reason is that they can be either plugged into a wall outlet or a wire connection box. No matter what, it requires its circuit.

Step By Step: Installing A Dishwasher

1. Measuring The Cabinet Space
It’s all about accuracy here. You’ll want to measure the cabinet width first – first in the back and then the front, if dimensions differ, take the smaller measurement. Repeat for height and length again, making sure you measure in two areas.

Measuring Dishwasher Cabinet

2. How To Wire A Dishwasher?
Lay the dishwasher on its back and unscrew the plate typically located below the dishwasher door. Locate the box and access it by unscrewing the cover. There you’ll see three wires – white, black, and multi-colored. Grab your power cord and reveal a bit of the copper wire, and pull it through the hole in the box. Twist together the wires matching the colors and afterward, place a wire nut on each twisted copper wire connection.

Copper Wire

3. Water Hose Installation
While the dishwasher lays flat on its back you should be able to locate a plastic hole looking like a garden hose. Take a 90-degree elbow and install it facing downwards. Then, grab a connector and water line hose and place them on the elbow, screw the connector nice and tight.

4. How To Cut a Cabinet?
Cutting cabinets is often necessary as you’ll have to either reach for the back to plug the dishwasher in or more likely, pull the drain and water line through to the sink. You’ll need a hole saw or spade bit attachment. Make 2 holes in the back of the cabinet, one on top that’s larger in diameter for the drain hose and another smaller one on the bottom for the water line hose. If your dishwasher is far away from the sink, make more holes in more cabinets.

5. Attaching The Dishwasher To Granite/Quartz/Stone/Corian Countertop
We’ll use the same and easiest procedure for all of these types of countertops. There are mounting tabs on top of dishwashers that you’ll use to mount later. You’ll have to purchase a mounting plate and install it on the sides of the cabinets.

Then, take the screws of the mounting plate, place the dishwasher inside, open the door, and screw in the mounting tabs to the plate. You don’t want any room left in between so make a test fit and adjust the feet on the bottom to fit the appropriate mounting height.

The reason for all of this is that you don’t want to drill holes in a solid countertop. If you have a wooden countertop, you don’t have to worry about mounting plates as you can place the screws directly into the wood.

Wooden Countertop

6. Drain Line Installation In Sink

  • Drain Line Into Garbage Disposal
  • Get a hose clamp and squeeze over the drain line end. If your garbage disposal is newer take the plug or knock it out first. Then, attach the drain line to the hole in the garbage disposal, take the clamp and tighten around it.

  • Drain Line Directly Into Drain
  • The same process occurs it’s just that you’re connecting it directly to your drain instead of the garbage disposal.

7. Water Line Into Supply Valve
You’ll take your water line hose and screw it onto the water valve end with your hand. Screw it tighter with pliers and turn on the water.

8. Installing The End Panel
First, you’ll make the support using 1” x 2” wooden planks. Make sure that they’re away from the cabinet at least 1/4” more than the size of the dishwasher. Once you’ve screwed in the support boards, take a plywood panel that you’ve already decorated and using corner braces, attach it to the outside walls of the L-support. Then you can add another plank to the front of the panel using corner braces again.

  • When you drill holes in tile for the support, try and avoid drilling the actual tile
  • Never stop measuring to make sure everything is straight

Corner Braces On Plank

9. Side Mounting
The side mounting holes are likely to be located in the dishwasher. You can open the door and remove the cap on the side to reveal a hole that you’ll screw in a nut to mount to the side cabinet. Alternatively, you can use a bracket, place it on the sidewall of the dishwasher, and screw in the hex screw in the designated holes.

10. Installing The Air Gap
Air Gap is mounted about 2” above the sink and uses backflow to prevent the wastewater from re-entering your dishwasher. They separate the dirty water running a hose from the drain running hose.

  • You’ll want to do this before the dishwasher is installed. Make sure to turn off the garbage disposal as well.
  • Buy the air gap. You’ll also need stainless s steel clamps and a 7/8” hose.
  • Take the air gap, place the clamp on the one tube end and attach a hose to it, then clamp it
  • Take the drain hose and attach it to the other tube end of the air gap. Use a clamp to seal it
  • You’ll have to make a hole in the countertop where the sink is to attach the last end at the top.
  • Grab the plastic screw that came with the air gap after you’ve pulled it through the hole and screw it in. Place the cap received on it once you’ve done it
  • Cut the 7/8” hose so that it comes straight down, there can’t be sagging where it comes back up once you connect it to the garbage disposal
  • Put a clamp on it and attach it to the garbage disposal, clamp it

Installing Different Types Of Dishwashers

We’ve discussed installing built-in dishwashers but not all people will like to cut down on their cabinet space to make it happen. Instead, they’ll buy a countertop or a freestanding dishwasher. Here’s how to install them

Countertop Dishwasher

The installation process of countertop model is pretty straightforward. They come with a tap adapter that you’ll connect to your water faucet. Then, you’ll connect the 2 hoses onto the tap and in the back of the dishwasher. Turn the faucet on to make the dishwasher work and you’re done.

Free-Standing Dishwasher

The standalone dishwasher installation process includes drilling holes in cabinets for drain/water hose and electrical wiring. It’s just that it doesn’t require mounting. You just have to make sure it’s leveled with the rest of your cabinets. if not, you can adjust its height with the bottom feet.

To Wrap It Up

There’s a lot of knowledge required to connect a dishwasher. If you’re confident enough, we do recommend you try and do it on your own but if not, we’d always suggest hiring a professional to do it as the wrong installment can potentially cause more issues and cost you more to fix those issues.

As an English major student at the time, Petra was stuck at home with online classes when the lockdown started. Soon enough, Petra discovered a passion for cooking and making pastries to pass the time. She started small with some experimenting and trying out new techniques inspired by French, Italian, and Asian cuisine. Since then, she has become a full-blown “little chef”, making dinner parties for her friends and expanding her knowledge with cooking classes.