Turn off the water supply and electrical breakers. Disconnect the drain and fill lines underneath the sink. Remove the dishwasher door by unscrewing the hinges and cutting the electrical cords. Unscrew the toe kick and remove.
Cut the electric lines connected to the back of the dishwasher and disconnect the drain and fill lines from the bottom of the machine. Leave the drain and fill lines, as well as the electrical wires, underneath the cabinet. If undamaged you can use the same connections with the new machine. Remove cabinet-mounting screws then slide the dishwasher out of place.
Inspect the drain and fill lines for cracks, if there are any, the lines will need to be replaced. If the dishwasher is old, it’s best to replace the lines to prevent future leaks.
Most new dishwashers come with a layer of insulation wrapped around the unit. Do not remove this as it acts as a sound barrier. Carefully tip the dishwasher on its back. Remove the panel at the bottom of the unit. Attach the elbow joints to the fill valve and drain lines. Wrap the threads of the joints in Teflon tape to create a water-tight seal. Wrap the Teflon tape in a clockwise direction to ensure it does not unravel when attaching the elbow joint. Make sure the elbow joints point towards the front of the dishwasher so that the fill and drain lines can be easily removed if service is required.
Reconnect the electrical and water supply lines and turn the dishwasher upright again. As you move the dishwasher back into place, feed the drain and fill lines into the space beneath the sink (Image 1). If there is a large gap between the cabinet and unit, adjust the height of the dishwasher legs (Image 2). Secure the dishwasher to the underside of the countertop by screwing it into place through the clamps located on the top of the machine. Once installed, turn the water back on and run a cycle to check the lines for leaks. When testing your new machine for the first time, don’t be alarmed if it doesn’t make a sound. Every dishwasher starts with a drain cycle. Finally, replace the toe kick at the bottom and remove the protective tape from the machine.