What is a Dishwasher Air Gap and Are They Necessary?

A dishwasher air gap is a small device that helps protect your dishwasher from backflow. Backflow occurs when dirty water mixes with the clean water supply. Many dishwashers don’t have built-in backflow prevention.

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A dishwasher air gap is usually installed on a countertop, near the kitchen sink. The tubing connections are underneath the kitchen sink.

Frequently Asked Questions (FAQs) About Dishwasher Air Gaps

What does a dishwasher air gap do?

A dishwasher air gap prevents dirty sink drain water from funneling into your dishwasher, which can contaminate your dishes. Kitchen air gaps help your dishwasher run optimally and keep your dishes in top-top shape.

Do dishwashers come with an air gap?

Surprisingly, many dishwashers lack built-in backflow prevention or an air gap. Some regulations require homes to have some form of backflow prevention.

However, an air gap might always be necessary. Some dishwashers have a drain hose looped upward and attached to the bottom of the countertop to prevent backflow.

How much does it cost to install an air gap?

The cost of installation can vary. You’ll have to consider the cost of the air gap device and parts.

As for installation, there are many resources on installing a dishwasher air gap. However, we recommend hiring a plumbing professional to have it properly installed.

Why is water coming out of my dishwasher air gap?

Occasionally, air gaps leak water, which may mean you need to run the garbage disposal. When an air gap leaks, the tube could have a kink or blockage.

You can quickly fix a leaky air gap by simply cleaning or inspecting it. Check the drain line below the sink by removing the air gap and inspecting the opening for obstructions.

What to do if your dishwasher has no air gap

Not having an air gap or backflow preventer makes it easier for dirty water to flow back into your dishwasher.

A few alternatives exist for backflow prevention. Install a high-loop or standpipe setup beneath the countertop, or a check valve in the drain line.

Backflow Alternatives:

• • • High loop: Routing a flexible drain hose connected to the dishwasher as high as possible under the sink. This prevents backflow by utilizing gravity, so the water cannot bypass. This method is easy to implement and compatible with most plumbing systems.
    • Standpipe: Installing a vertical pipe to a P-trap where wastewater can drop openly into the pipe. The hose attaches near the top of the standpipe, preventing dishwasher backflow from entering the standpipe.

  Type	Air Gap	High Loop	Standpipe
  How it Works	Separates wastewater so it cannot go into the dishwasher.	Gravity prevents backflow unless the main line is clogged.	Uses air brake if the hose end is higher than the pipe’s overflow level.
  Compliance	Universally required in most municipal plumbing codes.	May not meet stricter local plumbing codes.	When configured properly, they are usually permitted.
  Ease of Install	Moderate: May require drilling on the countertop or sink.	Easy: Can be secured using a zip tie or a bracket on the underside of the sink.	Hard: Requires plumbing work, a P-trap set up, and separate piping.

  No one method is better than the others, so it is best to choose the one that works best for you and your budget. However, we recommend hiring a professional to ensure backflow prevention is installed correctly and complies with plumbing code.

  By prioritizing backflow prevention, you keep your dishes and dishwasher safe and clean. This is good for you and your family.

  Why is backflow prevention important?

  Backflow can contaminate your dishwasher, causing foul odors and potential health issues. This is where kitchen air gaps come in.

  

  How to install a dishwasher air gap

  If you choose to install a dishwasher air gap, here are some basic instructions that can help:

  1. Gather your supplies. These supplies may include the dishwasher air gap, a screwdriver, and hose clamps.
  2. Choose your installation. Dishwasher air gaps must be installed on a countertop, so you must use an existing hole or drill a hole.
  3. Turn Off Your Dishwasher. Disconnect your dishwasher from its power source during this process.
  4. Connect the Drain Hose. Locate your dishwasher’s drain hose. This often flexible tubing can be found near the bottom or linked to the sink drain. You’ll need to connect this tube to the air gap with hose clamps to ensure a tight connection and prevent leaks.
  5. Attach the air gap to the disposal source. The air gap will need a place to siphon water from the dishwasher, so connect it to the sink’s drain or garbage disposal. Use a hose clamp to connect the other end of the tubing to prevent leakage.
  6. Install the air gap. If your air gap has a vanity cover, remove it before pushing the air gap fitting through the hole. You’ll do this from underneath the countertop.
  7. Check installation. Once you’ve pulled the air gap through the hole in the countertop, twist it to ensure it’s secure. You can reattach the vanity cover at this step.
  8. Test. Once you’ve finished your installation, you’ll want to test your handiwork. Reconnect your dishwasher to power and run a cycle. Check for any leaks during this cycle before resuming everyday use of your dishwasher.

  How to Clean a Dishwasher Air Gap

  You can clean a dishwasher air gap in a few easy steps.

  Step 1: Remove the vanity cover or cap.

  Step 2: Clean the interior of the air gap thoroughly. For best results, use a long-handled bottle brush to effectively remove gunk or food particles from the tubing.

  Step 3: Check for leaks. Once you’ve cleaned the dishwasher air gaps, check for any leakage from the tubing underneath the sink.

  Step 4: Make it Part of Your Cleaning Schedule. Add regular maintenance and cleaning for your air gap to your kitchen cleaning routine. This will help prevent future backups.

  

  A healthy home means having the right prevention measures in place. We hope this information helps eliminate backflow issues so you can keep your dishwasher healthy and well-functioning.