Before installing a dishwasher, run its entire cycle to ensure everything is working smoothly. Next, crouch or lie down to remove the front access panel and connect its power cord, water line, and drain hose.
If the old copper line is still installed, disconnect it by loosening its 90-degree fitting nut and replacing it with flexible stainless steel tubing.
Connect the Water Line
Enlist the assistance of another person to lift and position your dishwasher onto a piece of cardboard before inserting it into its cabinet opening. Locate its water inlet – typically round, threaded opening. Depending on your model, this inlet may feature female or male threads; which will determine what adapters you require; usually a 90-degree bend must be added at this inlet point to avoid kinking of water lines.
Now it is time to create the plumbing and electrical connections. First, make sure all power and water sources have been turned off at the circuit breaker or shut-off valve for your dishwasher – you can test this by turning on nearby outlets. After doing that, identify locations where tubing, drain hose, power cord and tubing need to be fed by removing the front access panel on the bottom of the dishwasher, as well as shaping copper tubing so it fits within each channel using a tube-bending spring or similar plumbing tool.
Connect the Electrical Cable
When connecting a dishwasher without hardwiring it, its cord will usually plug into a junction box that accepts it. Remove the cover of the wire connection housing and thread the power cord through it – connecting its wires with those found in the junction box (green to green, white to white and black to black) before reinserting its cover.
Your dishwasher may be connected to the water supply via a compression fitting that connects directly to the copper tubing leading from the shutoff valve under your sink, or via flexible hose connected to a flexible tee above its drain trap. In either case, a dual-outlet valve will be required; you should follow manufacturer’s instructions for installation of such an accessory.
When installing your dishwasher, always grasp it by its sides rather than its front to avoid denting it. Push it into place while making sure that no parts or hoses become pinched or kinked before adjusting its feet so it fits securely against your countertop.
Connect the Drain Line
Attract help from another individual when lifting and removing your dishwasher. While doing so, sponge out any standing water from the drain line. Also remove any screws securing panel covers to access its inlet valve (this is where home water feeds into it). If your model features a reversible pump with switch for selecting pumping water to spray arms vs drain line use; upgrade this switch with one featuring an integrated branch tailpiece (available from plumbing supply stores) which connects directly with sink drain.
Make use of a drill and spade bit or hole saw to drill a 1-1/2″ hole for the drain hose in the cabinet wall, using as high up in the dishwasher alcove as possible for optimal performance and to avoid kinking in its line. Some plumbers advise against placing this hole closer to the base cabinet than necessary.
Connect the Supply Line
You must connect your dishwasher to the home water supply and drain line and drain hose before connecting it. Start by turning off power at your circuit breaker and water at your house valve; use a noncontact voltage tester to confirm there is no current flowing through electrical cables; connect and start.
Locate the dishwasher’s water inlet, which should be a round threaded opening (Photo 2). Depending on its design, this may feature male or female threads or may require adapters. When connecting the water supply line to it using an adjustable wrench, tighten it onto this opening by tightening its screw. For an additional layer of leak protection, wrap its threads with Teflon tape for leak-free connections.
Screw a 3/8-inch hose fitting onto the end of your water supply line and feed it through your dishwasher hole, connecting to either your sink tail pipe or garbage disposal as per manufacturer instructions. Some systems require an air gap between drain hose and disposal to prevent backwash into your dishwasher.