How to Install a Dishwasher

Due to the plumbing work involved, installing a dishwasher may at first glance appear to be a daunting task. However, for the average DIY enthusiast, it is a fairly straightforward project that can be tackled with some basic knowledge and proper use of the installation manual. For those installing a dishwasher for the first time, choose a spot close to the sink, where the door is able to open fully and unobstructed.  The guidelines provided here should be considered general advice that offers an overview of the work involved. When it comes to the actual installation, always follow the instructions included with the machine, accurately and fully.

Getting Started

Once you have found an appropriate space for your dishwasher, begin by turning off the power and placing a sheet of protective plywood on the floor. Keep in mind that the dishwasher must connect to the sink and will require a GFCI protected, 120-volt electrical receptacle. This connection generally involves a length of copper tube, typically measuring 3/8" in outer diameter. A second connection is required in order to dispose of the waste generated by the dishwasher. A flexible hose is used for this, which can be attached either to a tee above the sinks drain trap or to the garbage disposal.

Local Air Gap Requirements

Local codes and building standards relating to the installation of dishwashers vary, but in most places an air gap is required to be integrated prior to the garbage disposal connection. The role of an air gap is to prevent wastewater from flowing back into the machine and these devices will need to be purchased separately. They are mounted next to the sink using flexible hose. In the case that an air gap is not required, simply shape the drain hose into a high arc shape.

Replacing an Existing Dishwasher

In many ways replacing a dishwasher is simpler than installing one for the first time. The placement is decided for you and it’s likely that the air gap and connector outlets are already in place. Naturally, the only addition to the workload is de-connecting and safely removing the existing appliance. The first step is to turn off the power and water supply by locating the shut off valve under the sink. If the existing dishwasher doesn’t have a dedicated shut off valve, you will have to turn off the water to the property before draining the pipes by opening a faucet. You may want to consider installing a dual outlet shutoff before installing your new unit to avoid any inconvenience in the future. In order to complete the removal of the dishwasher, simply follow the installation instructions in reverse.