Check with your Building Inspection Department for local code and inspection and permit requirements for a dishwasher. Most usually call for a dedicated dw electrical circuit and an air gap.
It should have a dedicated 110v electrical circuit outlet (usually best put behind it). It normally doesn't have to be on a GFCI. If it ever trips a GFCI, and it's installed behind it instead of under the sink, you'll have to remove the dw from the cabinet to get to it to re-set it. The breaker should trip anyway if there's a problem.
If you're going to have to run a new circuit, I would run it off a 20 amp breaker with 12/2-with-ground wiring in case someone ever wanted to put in a heavy-duty dw. (Code and dw manufacturers usually just call for 15 amp with 14/2wg wire circuit.)
If you don't have a disposal with dw connection, you will have to install a new tailpiece with a dw "Y", preferably under the nearest side of the kitchen sink, for the drain hose connection. Loop the drain hose over the dw, either directly to the "Y" or above-the-sink air gap and then to the "Y" if an air gap is required.
If you have a disposal with a dw connection, don't forget to use a hammer and screwdriver to remove the plastic knock-out plug down in the disposal dw pipe before attaching the drain hose.
Check the particular dw for water connection instructions. Cold is O.K. on most new ones, but I always just connect mine to the hot water line. Whichever, use a separate dw water shut-off valve off of a "T" in the line to connect the dw supply line (may need to buy the supply line separately).
If you're ever planning on adding tile or a wood floor in the kitchen, now is a good time raise the cabinet base (shim up at least the thickness of the tile or flooring). If you install a dw in a cabinet base sitting on vinyl flooring and later someone adds tile for instance, it will trap the dw under the cabinet.
Last edited by Mike Swearingen; 05-22-2005 at 01:17 AM.