How to Install an Under Counter Dishwasher

You old dishwasher has probably seen better days. It may be time to get a new one if your dishes come out looking the same as they went in or if the front is very dinged up. Upgrading to a new, energy-efficient one could save you time doing the dishes as well as money on your power and water bills. Installing your new dishwasher can be done in as little as two hours.

Difficulty: Moderate

Instructions

Things You'll Need:

• Dishwasher with installation kit
• 3/8 inch to 1/2 inch brass elbow
• Teflon tape
• 10 foot of 1/2 inch soft copper
• 1/2 inch compression fittings
• Electrical wire nuts
• Cable clamp
• Plumber's strapping
• Adjustable wrench
• Level
• Screwdriver
• Drill with 2-inch hole saw

Prepare cabinet

1. Shut off water and power supplies.

2. Use a drill and 2 inch hole saw and cut a hole 3 inches from the floor and 2 inches from the back wall on the side of the cabinet next to the dishwasher bay. If the hole is below the cabinet floor, make two 1-1/4 inch holes on the cabinet floor near the back.

3. Thread the copper supply line from the dishwasher bay through the cabinet holes. Insert a tube-bending spring inside the end. Shape the tubing toward the water valve and then down toward the cabinet hole. Do not kink the line. Put a compression nut and then a ferrule over the tube end. Attach the line to valve and tighten the nut over the ferrule.

4. Measure the distance from the water pipe and wiring channels to the side of the dishwasher. These channels are clear paths on the underside of the dishwasher and are meant to protect the tubing and wiring from the motor. Mark position of channels on bay floor.

5. Bend the copper tubing with outside bending spring so that it comes down the cabinet side and aligns with water pipe channel mark. Tape the tubing to floor. Lay the electrical wire on wiring channel mark and tape to floor.

6. Protect the floor with a tarp and move the dishwasher on its back. Remove the cover panel at the bottom of the unit and locate the water inlet. Wrap teflon tape around the inlet's threads and screw brass elbow into inlet. Tighten with adjustable wrench.

7. Upright the dishwasher. Position it in front of the bay and line up the channels with the tubing and electrical wires. Push the drain line from the dishwasher through the cabinet. Slide the dishwasher in place while someone guides the drain line through the cabinet.

8. Use an inside bending spring to turn the copper supply line toward the elbow at the base of the unit. Leave 2 inches of straight copper and cut off excess. Put a compression nut and then ferrule over the end of the pipe and tighten nut onto inlet.

9. At the electrical connection, put a cable clamp over the sheathing of the exposed wires and tighten. Unscrew the nut on the clamp. Push the wires and threaded end of the clamp through the hole in the junction box. Put the nut back on the clamp from inside the box and tighten with a screwdriver.
   Use wire nuts to tighten like-colored wires together inside the box. Connect the green or bare ground wire to the mounting screw and tighten. Put wires in box and screw on cover plate.

10. Use a hose clamp to attach drain line to sink drain inlet. Attach the drain line to the back of the cabinet using plumber's strapping. The drain should make an arc that sits above the drain inlet.

11. Adjust the feet on the dishwasher so that the mounting brackets touch the counter and it sits level. Screw the mounting brackets to the underside of the counter. Replace panel cover.

12. Turn on water supply and power. Check for leaks at water connections.

References

• This Old House