Whether you are a brand new homeowner, or you’ve lived in your own house for 40 years, there are always new things to learn about how to take care of your home. An important part of your kitchen’s sanitation and plumbing is the dishwasher air gap. This small piece of equipment can mean the difference between sparkling clean dishes and a stinky mess. Read on to learn what dishwasher air gap is, why you need one, and what to be aware of as far as maintenance and repair are concerned.

What Is a Dishwasher Air Gap?

Most people have no idea what a dishwasher air gap is. Is it a space between your dishwasher and counter? Is it an air pocket inside that helps move the soap around? It’s actually an essential part of your kitchen’s plumbing. A dishwasher air gap (sometimes called a “kitchen air gap” or “kitchen sink air gap”) is usually a small metal cylinder near your sink faucet with a few holes in it, designed to prevent dirty water from draining back into your dishwasher. When your dishwasher pumps out the dirty, grimy water, it travels through a drain line into the air gap. Just like there is a gap between your sink’s faucet and the top of the sink so that no dirty water can flow into the faucet and contaminate the clean water, the air gap acts in more or less the same way.

What Is a Dishwasher Air Gap’s Purpose?

The dishwasher air gap purpose is to protect you and your family from contaminated water. The plumbing in your home, and specifically in your kitchen, is a delicate balance of pipes and hoses ushering out used water, and piping in clean water. If the two mix, it leads to contamination, harmful bacteria and general nastiness.

If you’re looking around your kitchen and are worried that you don’t see one, fret not. Not every home has an air gap. Instead of the actual cylinder on the counter, some states only require a high loop under the sink that connects through your garbage disposal. Both the dishwasher air gap and the high loop serve the same purpose: they both use gravity to get the dirty water out and keep the clean water uncontaminated. The drain line that goes from your dishwasher travels to the air gap or through the high loop under your sink and through the garbage disposal. The drain hose is lower than the hose connecting the clean incoming water, guaranteeing that the two will not mix.

Just like if your sink clogs, the air gap ensures that if there is a clog in the plumbing somewhere, the dirty water will drain out from the air gap and won’t contaminate the clean incoming water. It is also a protection for standing water in your dishwasher. If your drain hose is somehow clogged, the air gap will ensure that the dirty water doesn’t stay stuck in the dishwasher but actually empties into your sink.

What Should You Do About It?

Now that you understand the importance of an air gap for dishwashers and how they work, it’s important to make sure that the air gap continues to work at peak performance. Most states do have a plumbing code requirement for an air gap that would have been checked during initial installation, probably back before you moved into your home. However, codes change, people move, and appliances are updated. While a certified plumber would be very aware of your state’s codes, the dishwasher installer may not be. Whether you have a high loop under your sink or an air gap on your counter, it’s best to have a professional plumber take a look if you suspect there is something wrong.

With that being said, air gap maintenance is fairly straightforward. If your dishwasher begins draining slowly, is leaving behind grime, or starts to smell, you’ve most likely got a simple clog in your air gap. The first place to look for a clog is in the hose that connects the air gap to your sink or garbage disposal. Remove the hose and clean it out with a snake, hanger, or dowel.

You can also check where the hose connects to the garbage disposal to see if there is a “knock-out” plug still intact. This would only be for brand new garbage disposals, so it’s unlikely but worth a look.

If neither of those options have worked, you may have a leak in the drain hose. To check for a leak, reconnect the hose to the air gap but leave the other end removed and point it into the sink. Run your dishwasher and jump to the rinse cycle. Watch the hose to see if there are any obvious leaks that need repairing. You can replace the entire hose if necessary or use epoxy for a DIY solution. If none of these quick fixes have helped your dishwasher run better, it may be time to consult a professional.

Check Your Dishwasher Air Gap Frequently to Keep Your Dishwasher Running Smoothly

Dishwasher air gaps and their brothers, high loops, are essential aspects to your kitchen’s sanitation and smooth operation. If you are replacing appliances, updating your kitchen sink, or having any trouble with your dishwasher, make sure that your dishwasher air gap is set up properly. The more you know, the more confidently you can let you dishwasher do all the hard work.

Tired of not having a home warranty and paying out of pocket?

Give your home systems and appliances the protection it needs with a Home Service Club home warranty

Get a Quote

It only takes a few seconds.