How to Install a Dishwasher Air Gap

What You'll Need
Safety glasses and gloves
Drill (preferably cordless)
Rubber hose in both 7/8 inch, and 5/8 inch
Hose clamps
Dishwasher Air Gap Kit

The dishwasher air gap is often required by code, and must be fitted in order to prevent water from flowing back into drinking water and other systems. There are a few dishwasher air gap designs available, but the most easily used are those bought from home improvement stores in a kit. The air-gap kit is designed to be installed next to a sink or faucet, and has pipes which lead from the faucet to the dishwasher. The creation of an air gap allows you to safely use a dishwasher in the home, but if you are unsure about installing one, here are a few simple tips to help you get the job done.

Step 1  - Clear the Ground

The most important thing you can do is check that the air gap you are creating will be accepted by the local building codes. Your sink plumbing may need to be modified completely in order to install the gap. Once you're ready to begin, place towels around the sink, with the bucket directly under the pipes. Drill a hole in the sink with the drill.

Step 2 - Install the Kit

Remove the cover from the air gap device. Take the cover, and place it away from the other pieces. Twist the mounting nut, and then remove the rubber washer from beneath the nut. Place the washer onto the stem of the air gap, and then install the device through the hole you drilled in the sink. Get an assistant to place a fiber washer into the air gap stem above the sink, and then hand-tighten the nut until all of these pieces are tight.

Step 3 -Completing the Installation

Use the wrench to fully tighten the nut. You or your assistant should be screwing the nut while the other holds the system up in order to prevent it completely twisting around while the tightening is going on. After this is complete, add a section of both hoses to the ends of your air gap, and then place the other ends in the garbage disposal (7/8 inch) and your dishwasher (5/8 inch). Secure the hose ends using the hose clamps, which can be adjusted to tighten around the ends.

Step 4 - Finishing up

Once you're satisfied that the clamps are tightly fitted around the hoses, you should set your dishwasher for a spin while checking the air gap and hoses for leaks. Look at the areas where they're connected to the dishwasher, and places around the hole drilled in the sink. If you spot water coming from any part of the connection, then you should either pause the dishwasher (if you can), or wait until the end of the cycle and then check all of the fittings. The biggest problem may be the hose clamps, as these need to be fully tightened or they can work themselves loose and allow water to leak through gaps. Once you have tightened these up, try the dishwasher again, and repeat until your floor remains dry.