A Dishwasher can be a huge time saver and add convenience to your life. However, if you don't have one, it can be quite inconvenient to put one in. I installed one from scratch at my kitchen project in Inglewood and thought I'd cover the basics for you.
1. Make a spot for it. Dishwashers need a 24" wide hole in your cabinets, hopefully right next to the sink for easy access both for the user and for the plumbing hookups. This kitchen had a 24" wide base cabinet that was the perfect location for a new dishwasher. I removed the doors, drawer & shelf and then carefully started removing the cross pieces.
If you have room for the jigsaw, use that, but for removing the floor of the cabinet I needed my reciprocal saw. Get the dishwasher out and measure it to make sure of the exact dimensions. Drill at least a 3/4" hole from the new cavity into the sink cabinet. Sometimes you'll need two of them.
2. Add the Electrical connections. Dishwashers need to be on their own dedicated 20 amp circuit. Sometimes you can get away with including the garbage disposal on this circuit. If you're doing this, now's the time to take care of it while you can get to the wall to add the switch, etc. It's best to have a licensed (and competent :) electrician handle the electrical work.
My project had an open basement underneath which greatly reduced the difficutly in running the new circuit. I know this not always the case. You may have to get creative, but don't try to cheat and add the dishwasher to the countertop circuits.
3. Connect the plumbing. Usually, a dishwasher has a flexible pipe that goes through a hole into the sink cabinet to connect to the sink supply lines. A 3/8" compression fitting is standard, though it may have 1/2". This particular dishwasher was supposed to be connected to the hot water line. I installed a two-way valve that would control both the faucet and the dishwasher flow. (There were no valves there when I started. Crazy, I know.)
Hmm... Should you connect your dishwasher to the hot or cold water line??
This is a good question. It turns out that the answer is: "It depends." The best way to find out is to look in the installation manual from the manufacturer. If you don't have one try a search for your dishwasher model online.
Newer dishwashers are able to heat the water so they are classified as "cold-fill". They are connected to the cold supply line. However, older dishwashers don't have this feature and will need to connect to the hot water line in order to have hot water washing the dishes.
Go ahead and connect the water line under the dishwasher while you can easily access it. In addition to the supply line hookup, you'll need a drain tailpiece that has a dishwasher spout like in the picture above. That's where the dishwasher drain will connect to the sink drain.
4. Add the dishwasher. Having made these preparations, it's time to slide the dishwasher into its new home. As you do, pull the drain and supply line through those holes you made into the sink cabinet. Push the dishwasher all the way back and level it using the adjustable feet on the front. I like it to be fairly snug with the countertop, but make sure the door opens and closes freely.
5. Make the connections. The panels below the dishwasher remove to give you access to the connections. The electrical wire will enter the small box on the right through a clamp-connector that screws down to keep the wire from moving. Then you connect white to white, black to black and ground to ground. Sometimes the ground will also connect to a screw mounted somewhere in the box.
If you didn't already connect the supply line you can do this now as well as attaching the drain hose to the kitchen drain under the sink.
6. Test. Before you cover everything up take time to turn the water and electrical on and go through a cleaning cycle. Check for any drips and adjust as necessary.
It may take a day to get it all installed from scratch, but think of all that time you'll save by not hand-washing dishes! Guys, you may score some points with the wife as well... :)