7 May, 2023
How to Hook Up a Dishwasher Under the Sink

If you’re thinking about installing a dishwasher under your sink, the process can be a bit tricky. Generally, you need to get the electrical supply and water line connections in place before the dishwasher itself can be installed. This may require a little extra work on your part, but it’s still doable with some planning and preparation.
Start by turning off the electricity to your kitchen at the breaker box and turning off the water at the stop valve under your sink or at the service panel in your house. This will help to protect you from a possible electric shock or water leak while removing and installing the new appliance.
Make sure to use small pails on hand to catch any water that might spill as you dismantle the old dishwasher. This is especially important if the floor is raised above the countertop in front of the existing machine.
Next, you’ll need to remove the screws holding the dishwasher to the cabinetry. This can be a time-consuming step, but it’s essential to make sure the dishwasher doesn’t fall over and scratch the floor while you work. Depending on the condition of the cabinetry and your own skill level, you may need to hire a professional installer to do this job for you.
Then, use a tubing cutter to cut away the existing plumbing line connected to the old dishwasher under your sink. This will allow you to fit a new drain hose onto the existing branch tailpipe underneath your sink, which will then connect to your garbage disposal or sink drain.
Once the plumbing connection is complete, you can move on to reassembling the cabinetry and hooking up the dishwasher itself. This will be a time-consuming and difficult task, but it’s essential to get the dishwasher in place and working before you can turn on the power or start using it.
You’ll need a hole saw for this project, but you can also use regular drill bits if you don’t have one. You’ll also need a wrench and some plumber’s tape to connect the new supply lines to the shut off valve and the inlet under the dishwasher.
If your kitchen cabinetry doesn’t have the right sized holes already in place, it will take more effort to install the supply lines from your dishwasher. It could mean making them bigger or adding additional holes for the new hoses.
Measure the supply lines, both for the electricity and the water, and mark the channels where they will run along the sides of your dishwasher. Transfer these measurements to the floor of your cabinet, then use a tube-bending spring to shape copper tubing so that it travels along the supply lines and into the channels you marked.
Now, you can remove the cover from the wire connection housing inside the base of the dishwasher, and thread the dishwasher’s electrical cord into it. You will need to make three wire connections: the green (ground) wire from the appliance cord to the green ground screw, the white neutral wire to the white dishwasher lead, and the black hot wire to the black dishwasher lead. These connections are normally made with twist-on wire connectors (wire nuts) but some appliances may have different methods for connecting the wires.