How to Install and Connect a New Dishwasher

Installing a new dishwasher is easy with the right steps—here's how

Dishwasher being installed with screwdriver

The Spruce / Kevin Norris

Project Overview
  • Working Time: 2 - 3 hrs
  • Total Time: 2 - 3 hrs
  • Skill Level: Intermediate
  • Estimated Cost: $20 to $40 (excluding appliance)

When you buy a new dishwasher, the price might include the delivery team installing the dishwasher hookups and hauling away the old dishwasher. But it is usually not included if you buy the dishwasher from a big-box home improvement center or an online retailer. It may be a substantial additional fee, ranging from $110 to $270, whether installing a dishwasher for the first time in a new kitchen or if you need to install a dishwasher in existing cabinets.

Fortunately, connecting the dishwasher yourself is pretty straightforward once the old dishwasher has been removed

Before You Begin

Connecting a new dishwasher requires three connections: a power cord connection, a water supply connection, and a drain line connection. DIYers can do all of these if they understand what's required. 

Power Connection

The power connection may be the trickiest, especially if you don't have experience with electrical wiring. The National Electric Code (NEC) requires that a dishwasher be served by its dedicated circuit, and if yours is not wired this way, you may want to have a new circuit installed while you are replacing the dishwasher. As of 2020, the NEC also requires that dishwashers have GFCI protection, which makes it easier to disconnect the appliance if it needs future servicing.

  • NM (non-metallic) circuit cable: Dishwashers can be "hard-wired" with an NM circuit cable that feeds directly into the dishwasher's wire connection box.
  • Standard appliance cord: More commonly, they can also use a standard appliance cord plugged into a wall outlet.

There is no reason you can't wire the dishwasher yourself. Both hard-wired connections and appliance cord connections are done the same way, with wire connections made inside an access panel at the base of the appliance. 

Water Supply Connnection

The water supply connection is easy to connect. One end of a braided steel supply tube is attached to the dishwasher's water inlet valve and the other to a shut-off valve on a hot-water supply pipe. This supply tube is a longer version of the same ones that feed sink faucets and toilets, so if you've worked on those plumbing fixtures, you'll have no trouble with the dishwasher hookups.

Hooking up the water supply tube to the dishwasher usually requires attaching a special brass fitting known as "dishwasher 90"—a 90-degree elbow that allows the supply tube to connect to the dishwasher easily. This fitting is normally included with the connection kit, consisting of the braided steel supply tube. 

Drain Hose

Connecting the drain hose on a dishwasher is an equally simple plumbing job. The drain hose connects to the drain trap under your sink; on the way to the trap, it either loops up to the underside of the countertop or is attached to an air-gap fitting.

The proper method of doing this depends on the code requirement in your area and is intended to keep dirty wastewater from siphoning back into your dishwasher. As the drain hose loops back down, it is attached either to a nipple on the garbage disposal or directly to a nipple on the sink drain tailpiece.

What You'll Need

Equipment / Tools

  • Screwdrivers
  • Channel-lock pliers or adjustable wrench
  • Drill and spade bit (where necessary)

Materials

  • Dishwasher connector kit
  • Pipe joint compound
  • Electric appliance cord
  • Wire connectors (wire nuts)

Instructions

Materials and tools to install a dishwasher

The Spruce / Kevin Norris

How to Install a Dishwasher

  1. Identify the Access Panel

    The electrical hookups and the plumbing connections are behind an access panel on the dishwasher's front bottom.

    • Lay the dishwasher on its back to remove the access panel and make the preliminary connections. 
    • Remove the bottom access panel on the dishwasher.
    • Visually identify the power cord connection fittings, the water inlet solenoid valve, and the drain fitting. 
  2. Attach the Electric Cord

    • Remove the cover on the wire connection housing.
    • Thread the power cord into the housing, and make the three wire connections: green wire from the appliance cord to the green grounding screw, white neutral wire to white dishwasher lead, and black hot wire to black dishwasher lead. These connections are typically made with twist-on wire connectors (wire nuts).
    • Replace the cover on the wire connection housing. 
    Electric connections hooked up in dishwasher access panel

    The Spruce / Kevin Norris

    Tip

    If there are not already access holes drilled in the side of the base cabinet, drill holes to run the power cord to the outlet and the drain hose to the garbage disposal or sink drain. 

  3. Hook Up the Water Supply

    Your dishwasher connector kit includes a dishwasher 90 that will serve to connect the water supply to the dishwasher. Installing the dishwasher 90 is the first step to hooking up the water supply for your dishwasher.

    • Locate the water inlet fitting on the solenoid valve.
    • Apply some pipe joint compound to the threads of the dishwasher 90 fitting, then thread it onto the solenoid valve.
    • Tighten fully by hand, then tighten an additional 1/4 turn with channel-lock pliers or an adjustable wrench.
    Water inlet fitting added to dishwasher solenoid valve

    The Spruce / Kevin Norris

  4. Attach Water Supply Line

    The dishwasher connector kit also includes a braided steel water supply tube.

    • Thread the supply tube coupling nut onto the dishwasher 90 fitting and tighten it with channel-lock pliers or an adjustable wrench. Be careful not to overtighten, as it is possible to strip the threads. 
    • This is a compression fitting that does not require pipe joint compound. 
    Water supply hose connected to dishwasher 90 fitting

    The Spruce / Kevin Norris

  5. Position the Dishwasher

    • Turn the dishwasher right side up.
    • Slide the dishwasher under the kitchen counter, feeding the power cord, the water supply tube, and the drain hose through the holes in the sidewall of the cabinet. Line the appliance up to the center of the opening without pushing it too far back.
    • Use the adjustable legs to raise and level the dishwasher, following the manufacturer's directions. Unscrew the legs with pliers, if necessary, to bring the dishwasher up to counter height and level it.
    Dishwasher positioned under marble kitchen counter

    The Spruce / Kevin Norris

  6. Anchor the Dishwasher

    • When satisfied with the dishwasher's placement, fasten it by opening the door to access the mounting brackets.
    • Use the screws provided to fasten the brackets to the cabinet frame under the lip of the counter.
    Dishwasher anchored with mounting brackets and electric drill

    The Spruce / Kevin Norris

  7. Connect the Water Supply Tube

    • Connect the end of the water supply tube to the water supply shutoff valve under the kitchen sink. (In a new installation, you may need to install this shutoff valve on the hot water pipe.)
    • Turn on the shutoff valve.
    • Check for leaks by looking under the dishwasher and at the other end of the supply tube connecting to the dishwasher 90 fitting.
    • If you notice leaks at either location, gently tighten the fittings a little more.
    Water supply tubes connected to shut-off valve under kitchen sink

    The Spruce / Kevin Norris

  8. Connect the Drain Hose

    • The rubber dishwasher drain hose is usually already attached to the dishwasher. If not, it can be secured now using a hose clamp. 
    • Depending on the configuration of your sink and local code requirements, there are several possible configurations for the drain hose.

    Watch Now: 4 Methods of Making Dishwasher Drain Connections

    • Air-gap fitting: The dishwasher drain hose can be attached to an air-gap fitting mounted on the countertop or sink deck. A second hose runs to the garbage disposal or the sink drain tailpiece. The hose from the dishwasher is usually attached to the air gap with a spring clip, while the hose connects to the garbage disposer with a hose clamp.
    • High-loop connection: The dishwasher drain hose may be looped up and secured to the underside of the countertop, then dropped back down to connect to the garbage disposal or sink drain tailpiece. A "high loop" works like an air gap, preventing water from backwashing. Local codes may not allow this method.
    Rubber drain hose connected to sink drain tailpiece

    The Spruce / Kevin Norris

  9. Test the Dishwasher

    • Plug in the dishwasher’s electric cord.
    • Before putting the face plate on the front of the dishwasher, test it by running the dishwasher through a complete cycle.
    • Ensure fresh water is being taken in and drain water is flowing properly, with no leaks.  
    • The final step is to put the face plate back on the bottom front of the dishwasher.
    Dishwasher being tested after installation

    The Spruce / Kevin Norris

When to Call a Professional

Making new electric or water connections for the first time is not easy, and people with little experience or not comfortable with it should consider hiring a plumber, electrician, or contractor. Electric codes require that a dishwasher needs to be on a separate circuit.

If you install a dishwasher in a new space or remove existing cabinetry, this job might be more significant than you expect and more than you should tackle on your own. When a plumber does all the water connections, you minimize the risk of leaks and other potential problems down the line.

FAQ
  • Can I install a dishwasher myself?

    You can install your dishwasher, but it requires some expertise and careful attention to detail when making your connections.

  • Do you need a special hookup for a dishwasher?

    A dishwasher requires three lines—a power cord, a water supply line, and a drain line. You will need a special brass fitting known as "dishwasher 90" to connect the water supply tube to the dishwasher. 

  • Do dishwashers use hot or cold water supply?

    Dishwashers are connected to the hot water line since they all use hot water during washing.

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  1. How much does dishwasher installation cost? HomeAdvisor.