How to install a dishwasher

Updated February 21, 2017

Installing a dishwasher isn't the major task many people seem to think it is. Dishwashers are made to fit into a standard 24" wide space and fit under a counter top that's about 34" high (standard countertop height). If your house has such a space (and most do) or you can remove an existing cabinet that has these dimensions you can probably install a dishwasher. While not difficult, the installation requires knowledge of basic plumbing and electrical connections as well as some familiarity with using tools. This article assumes you have the appropriate space available.

Here's what you'll need Electric drill and hole cutting bit Screwdrivers Pliers Adjustable wrench Level Teflon pipe tape Drain pipe for dishwasher Dishwasher connection kit - available at your home store (should contain water supply line for dishwasher as well as necessary connectors and compression couplers). New dishwasher

Determine that you have access to the hot water supply line, the drainpipe and an electrical connection under the sink. Installing the dishwasher will require extending the hot water supply line to the dishwasher, connecting the dishwasher drain to the drainpipe under the sink, and plugging the dishwasher in. If your home was not plumbed in anticipation of a dishwasher, you will need to change some fittings under the sink to make these connections possible. (See below)

Read the instruction manual that comes with your new dishwasher. Installing a dishwasher is straightforward but you want to be sure you understand and are comfortable with the necessary steps.

Measure and slide the dishwasher into place to test fit the space then slide it out.

Drill a 3" hole in the cabinet wall separating the dishwasher from the cabinet space under the sink. (If there isn't one already there).

Attach the drain hose to the output of the dishwasher- usually attached with a small hose clamp. (This hose often comes with the dishwasher itself, but if you don't get one they are available at a home store).

Attach the water supply line to the hot water input valve on the dishwasher. These connections are compression fittings - just tighten them, no soldering necessary.

Using wire nuts, attach the electrical wiring to the small junction box on the dishwasher and close the box. (Black to black, white to white and green or copper to green or copper).

Slide the dishwasher into place while threading the connections through the hole in the cabinet wall.

Connect the dishwasher's drain tube and water supply tube to the sink drain and water pipe under the sink.

Check for level and shim the dishwasher if necessary.

Install the mounting screws that hold the dishwasher in place to the underside of the cabinet lip. These are usually 2 small (1/2") screws.

Plug the dishwasher in and give it a test run to check for leaks. Tighten any connections that might be leaking.

Install any finish molding and your job is done.

Shut off the hot water supply to the sink and drain the line.

Align the "T" fitting with the supply pipe and mark the supply pipe where the fitting will be installed.

Using a pipe cutter cut out the marked section of the supply pipe and insert the "T" fitting so that the output faces towards the dishwasher

Tighten the hex nuts on the compression coupling.


Apply Teflon tape to the threads of all compression fittings before you tighten them. This will help stop any annoying drips. Be careful you don't overtighten a compression fitting. If you tighten them too much you may damage the internal seal and actually cause a leak. When you are sliding the dishwasher into place a thin piece of scrap plywood or an old blanket will protect your floor.

Things You'll Need

  • dishwasher
  • supply and drain tubes
  • "T" fitting
  • adjustable wrench
  • Teflon tape
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This article was created by a professional writer and edited by experienced copy editors, both qualified members of the Demand Media Studios community. All articles go through an editorial process that includes subject matter guidelines, plagiarism review, fact-checking, and other steps in an effort to provide reliable information.