How To Install A Dishwasher

By Todd Fratzel on Plumbing

Installing A Dishwasher

Dishwasher Hookup DiagramInstalling a dishwasher is a fairly easy to intermediate home improvement task. If you already have a dishwasher installed and you have the proper water shut off valves than installing a new dishwasher is very straightforward.

As with any home improvement project make sure you follow the manufacturers instructions carefully and obey all local laws involving plumbing and electrical codes. The first step should always be to shut off both the electrical power supply and water supply to the existing unit. The water supply shut off valve is typically located in the cabinets below your kitchen sink. The power supply should be hooked up to an independent breaker in your main service. After you shut off the electrical breaker make sure you test the power to verify that it’s shut off.

Dishwasher Disposal DrainRemove the lower toe-kick cover plates on the old dishwasher. This is where you’ll disconnect the power supply and the water supply. The power is almost always located on the right hand side. There should be some kind of cover plate over the electrical junction box. Remove the cover and remove the wire nuts to the black and white leads. Disconnect the ground wire and make sure any bushings on the electrical box are removed as well. On the left side should be the water supply line. Typically the water line will be either soft copper pipe or a stainless steel braided water line. Disconnect the water supply line and have a small cup or bucket handy so you can catch any excess water in the line. Now you’ll need to disconnect the drain line. If you have a garbage disposal the dishwasher drain will be connected with a small corrugated white drain line. Disconnect the drain house and again drain out as much of the excess water as possible.

At this point you should be able to remove any screws holding the dishwasher in place. Typically the screws are either attached to the counter top or sides of the cabinets. Some dishwashers are now being screwed into the floor along the bottom steel runners (this is due to the popularity of granite counter tops that cannot be drilled into). Once you remove the screws you should be able to remove the old dishwasher from under the counter top.

To install the new dishwasher you’ll basically reverse the previous steps. Again remove the lower toe-kick cover plates so you can access the electrical junction box and the water supply line connection. As you slowly push the new dishwasher under the cabinet make sure you guide the drain line back through the cabinets into the sink base. Make sure you grab the electrical wires and water supply lines and pull them forward as you slide the washer back.

Dishwasher Electrical HookupReconnect the water supply line and the black, white and ground electrical wires. Re-install the electrical junction box cover and make sure everything is tight and cleaned up. Adjust the dishwasher feet so that the dishwasher will be within a 1/4″ of the counter top. Push back the dishwasher and install the screws that secure the unit (into the counter top, into the cabinet sides or screws into the floor along the runners). Now connect the drain line back into the back of the garbage disposal and secure the clamp. Turn on the water supply valve and check for leaks. Turn on the power and run the dishwasher through a cycle so you can check for leaks. If you don’t find any leaks than re-install the lower toe-kick cover plates and you’re finished!

Products You Might Need to Buy:

As I said this is a fairly straight forward do-it-yourself project. Just make sure to take your time, shut off power and water and follow the manufacturers directions closely.

About the author

Todd Fratzel

I'm full time builder for a large construction company in New Hampshire. I run their design-build division that specializes in custom homes, commercial design-build projects and sub-divisions. I'm also a licensed civil and structural engineer with extensive experience in civil and structural design and home construction. My hope is that I can share my experience in the home construction, home improvement and home renovation profession with other builders and home owners. I'm also the Editor-in-Chief and Founder of Tool Box Buzz. Please feel free to contact me if you have any questions, suggestions or you'd like to inquire about advertising on this site.

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  1. Jennifer says:

    I like the new setup! It looks very professional.

  2. Ethan says:

    Great post (and blog format)! I haven’t had to work on my dish washer yet, but it may be the next major appliance we swap out.

  3. Todd says:

    Replacing a dishwasher sounds intimidating but actually it’s a really straightforward project.

  4. Jarrod says:

    I have a question about the ground wire. I have a long, copper wire that comes out of the existing electrical line and the instructions tell me to put it behind the “green” screw in the electrical box. This I get, however, my wires are extremely long and part of the ground wire will probably touch other parts of the box. Is this a problem? I don’t want to get shocked when trying to do a load of dishes.

    • Todd says:

      @ Jarrod – Not sure if I completely understand your question. However, the ground wire is always “bare” inside of electrical boxes and almost ALWAYS touches the box. Not worries for that situation.

  5. Jennifer says:

    Hi- Thank you for your help…I have one question. I reused my old water line successfully (so far) BUT am wondering if it is a problem to have that copper line touching any other parts under the dishwasher? I am thinking that that line gets pretty hot and should not be near or touching the plastic/rubber parts of the hoses but I have read/watched many DIY instructions and no one had any warning or precaution against doing this. My copper water line IS touching/very near the hose and I am not sure if this is going to be a problem but after a couple attempts, I was unable to move it far enough away and still be able screw it into the dishwasher. Should I replace it with a flexible water line or does it not get hot enough to matter?

    • Todd says:

      @ Jennifer – The water should not get hot enough to melt plastic or rubber hoses. As far as I’m concerned I would not move it. Best of luck!

  6. am says:

    i,m needs a schematic diagram and circuit diagrams of dishwasher. where can i get it.
    i’m need it for my final year project. hope you will help me out. please email me at

  7. Larry R says:

    I was wondering if you can use a standard electrical, heavy guage cord, so that you could plug into the outlet, instead of hard wiring with 12-2 romex. Thanks!

  8. Jose Manuel says:

    I have one of this model , but i dont know what kind of detergent can i use for this model and i dont know ¿where can i put the detergent?

  9. Amanda says:

    Hi Todd

    Need a wiring diagram for dishwasher Defy DDW 143. Can U help?

  10. Dan R. says:

    Thank you so much! this is exactly what I am looking for. I appreciate all the details, they have helped so much.

    Keep up the good work.

  11. Bill says:

    We are planing a kitchen and with the large island with sink it is 12′ from the dishwasher location. can you show how we can connect with out a GD or sink

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