Replace a Dishwasher


Today's dishwashers clean better, run quieter, and use less energy and water. Here's a guide to dishwasher installation.


  • Screwdriver
  • Adjustable wrench
  • Absorbent rag or shallow pan
  • Hose clamp
  • Rug or sheet of cardboard
  • Voltage tester
  • Dishwasher
  • Teflon tape
  • Pipe clamp
  • Auxiliary wire
  • Mounting screws
  • Level
  • Anchoring screws


  1. Shut off water and power

    Use a screwdriver to disconnect the discharge hose clamp running from the sink pipe to the dishwasher — keep the hose clamp to use for the new dishwasher.

    Use a screwdriver to pry off the access panel below the door and disconnect the hot water supply line (it's a flexible copper or braided stainless steel line) at the 90-degree copper elbow fitting near the bottom front left corner of the dishwasher. With a wrench, remove the elbow and set it aside with the other loose parts. Place an absorbent rag or shallow pan underneath the fitting to catch water that may leak from the line.

  2. Remove the old dishwasher


    Use a screwdriver to remove the anchoring screws. Place a rug or sheet of cardboard on the floor in front of the dishwasher to protect the floor and then ease the dishwasher from its opening — you can adjust the leveling feet to create more clearance.

    Repair any damaged flooring or cabinet boards before starting the dishwasher installation process.

  3. Disconnect electrical feed


    Remove the electrical junction box on the lower right front corner with the screwdriver. Attach the probe of the voltage tester to each wire to confirm that the circuit is off.

    To disconnect the electrical feed from the dishwasher, unscrew the wire nuts by hand and remove the romex connector (the round metal connector with two screws) with the screwdriver. In the junction box on the lower left front corner, disconnect the black and white wires and the bare ground wire attached to the box. Save the wire nuts and the romex connector.

  4. Connect the plumbing


    Connecting the plumbing before the electrical makes it easier to pull out the dishwasher if you find a leak.

    Place the new dishwasher on its back. Firmly wrap Teflon tape four times clockwise around the threads of the elbow and attach the copper elbow for the hot water supply line. Set the dishwasher upright and connect the water line to copper elbow by hand. Thread the discharge hose into the hole in the side of the cabinet carefully to avoid kinking the hose, and ease the dishwasher into the opening.

    Attach the compression fitting to the supply line using the wrench being careful not to over-tighten it or the line will kink. Test for leaks by turning on the water supply. If it leaks, adjust the compression fitting slightly until the leak stops.

  5. Attach the electrical feed


    Use a screwdriver to remove the junction box cover on the lower right front on the new dishwasher. Recheck the electric is off by using the voltage tester again. Use the wire nuts to connect each wire on the dishwasher to the matching color in the junction box. 

    Place the romex connector 1 inch back from the wire assembly and tighten it with the screwdriver. Tighten the bare wire to the green ground screw inside the box by hand and replace the junction box cover. Attach the drain line to the highest point in the sink cabinet with the pipe clamp.

  6. Create an air gap

    Most local codes require the use of an air gap to prevent backflow into the dishwasher.

    Mount the air gap on the back edge of the sink to the right of the faucet. The line vibrates during use, so wrap a couple lengths of wire around it and secure it with mounting screws to the underside of the countertop. Be careful the screws don’t poke through the countertop. Run one line from the drain line to the air gap and another from the air gap to the dishwasher drain outlet.

  7. Insert the dishwasher

    Slide the dishwasher into the opening. Use the feet on the dishwasher to adjust the height. Place the level across the face of the dishwasher to check whether it is sitting flush to the cabinets. Screw the dishwasher to the bottom of the countertop with the anchoring screws.

  8. Check for leaks

    Run the dishwasher through a cycle empty before you reattach the front access panel.