How to Hard Wire a Dishwasher
One of the few appliances in the kitchen that is wired directly to a dedicated circuit is the dishwasher. Aside from the heating element which draws a considerable amount of amperage, the dishwasher is connected to a water source which can pose an elevated risk to shock and circuit overload. Having other items connected to the same circuit can cause the breaker to trip.
As long as the circuit breaker is turned off the connection can be made fairly easily. If you are not comfortable with making the electrical connections for the dishwasher, you should hire a licensed electrician to install the appliance on the dedicated circuit.
Tools and Materials
This article goes over the electrical connections for the dishwasher and does not focus on the plumbing connections such as the water supply hook-up and drain hose. Make sure to shut off the water supply to the dishwasher before attempting any electrical work on the dishwasher or circuit.
The electrical connection for the dishwasher is usually on the wall behind the dishwasher opening, in the cabinet under the sink, or sometimes there will just be a wire sticking out of the floor or wall.
Electrical cable (white wire with yellow wire nuts) and no junction box
1. Turn Off the Power
Locate the breaker for the dishwasher and turn it to the OFF position. If there is a junction box installed, remove the cover plate and test the black wire to ground to determine that the power is off. Use a voltage tester to test the wires to make sure the circuit is off before you start working.
2. Preparing the wires
If you have an old dishwasher you are replacing, you should be able to use the existing wire. Inspect the cable sheathing and wiring to make sure that there are no tears, crimps, or scorch marks present. If there is any damage to the cable, cut it back to a good section and install a junction box on the wall. Cut a new of cable (12-2 gauge) about 4 feet long to feed the dishwasher from the junction box. Use a utility knife to remove the last 6-inches of sheathing from the cable to expose the wires. You may want to tape the end of the wire to the floor since the electrical connection is made in the front of the appliance.
Damaged wiring at the cable connector
Strip about ¾-inch of insulation from the ends of the white and black wires.
When the ends of both wires have been stripped, slide the cable connector over the end of the cable and secure it in place over the sheathed portion of the cable with the threaded end facing outward. Remove the locknut from the threaded end of the connector.
3. Secure the Cable
If you have installed a junction box you need to remove two knockouts; one for the cable coming from the panelboard and one for the cable going to the dishwasher. To remove the knockouts, hit the edge with a flat screwdriver or a pair of needle-nose pliers then grab the knockout with the pliers and twist it until it breaks free.
Take the wires and guide them into the box until the cable connector’s threads are on the inside of the box. Slide the locknut over the wires and secure the connector to the box.
4. Complete the Wiring
- Take the ground wire and secure it to the green ground screw on the dishwasher and tighten the screw.
- Make the connections for the black wire from the circuit and the black wire from the dishwasher twisting the wires together with pliers and capping them with a wire nut. Repeat this for the wire wires.
3. Wrap each wire nut with electrical tape.
4. Carefully bend the wires so they fit inside the dishwasher junction box and replace the cover plate.
5. Complete the water line hook-up and drain hose to the dishwasher. Check for leaks after turning on the water
6. Carefully push the dishwasher into the opening and secure it to the countertop with the screws supplied with the dishwasher.
7. Level the dishwasher by adjusting the feet in front with an adjustable wrench and 2-foot level.
8. Test the dishwasher operation.