How do I know if my dishwasher has an air gap?

Author: Casper Simonis  |  Last update: Friday, September 5, 2025

The air gap is a chrome plated cylinder located on the back of the sink where the faucet is located. Not all areas have plumbing codes that require an air gap, so you may not have one installed with your Dishwasher drain. The air gap prevents water from a clogged drain from backing up into the Dishwasher.

Do all dishwashers have an airgap?

It's important to note that some dishwashers don't require an air gap, so they won't always come with one, but there are alternatives that help keep your dishwasher water safe, like a high loop or standpipe.

What happens if my dishwasher doesn't have an air gap?

The truth is that any dishwasher will work without an air-gap; The air-gap has nothing to do with the machines operation, it is required to prevent cross contamination of grey water to the potable water. It is definitely in the Building codes.

What does an air gap look like?

This "air gap" is visible above the sink as a small cylindrical fixture mounted near the faucet. In the base cabinet under the sink, the drain hose from the dishwasher feeds the "top" of the air gap, and the "bottom" of the air gap is plumbed into the sink drain below the basket, or into a garbage disposal unit.

What happens if you don't have an air gap?

The use of an air gap is required by plumbing codes for certain plumbing fixtures, such as dishwashers, to prevent the backflow of potentially contaminated water into the clean water supply. If contaminated water backflows, it can cause serious health risks.

Now You Know: The Dishwasher Air Gap

What can I use if I don't have an air gap for my dishwasher?

However, high loops are popular, inexpensive to install and have proven to be reliable backflow prevention methods. If you opt not to install a dishwasher air gap, a high loop is the best alternative.

What are the two requirements for the air gap?

How Measured: Air gaps shall be measured vertically from the lowest opening of the water supply outlet to either (1) the flood level rim of the fixture or receptor served, or (2) the maximum elevation of the source of contamination.

What states require a dishwasher air gap?

If you reside in California, Washington, Minnesota, or Hawaii, installing a dishwasher air gap is mandatory per the plumbing code in these regions.

Why is water pooling in the bottom of my dishwasher?

CHECK YOUR DRAIN MOTOR, DRAIN VALVE AND DRAIN HOSE

A broken drain motor or a clogged drain hose can also cause standing water in your dishwasher. A stuck drain valve bracket may indicate burnt out electrical components in your dishwasher. All of these issues are better left to the professionals.

How much does it cost to install an air gap for a dishwasher?

How Much Does It Cost To Install an Air Gap? An air gap device for dishwashers can be bought for $10-$30 and installed by a qualified plumber, appliance installation service, or a handy homeowner.

Why is my brand new dishwasher not draining?

There are a few reasons why your dishwasher won't drain. The most common source of clogs comes from a blockage in the dishwasher's filter. Or, you may have an issue with your dishwasher's air gap, drain valve, drain hose or even your garbage disposal, causing your dishwasher to clog.

How do I prevent sink water from draining into my dishwasher?

When there is a clog in the line, and it's not draining properly, water pressure in the pipes can increase and force sink water up into the dishwasher drain line. One way to relieve the pressure is to disconnect the sink trap (P trap) underneath the sink and remove the blockage.

Does every dishwasher have a vent?

Most dishwasher have a vent opening at the top of the inner door panel. Earlier dishwashers vented the hot air through the upper part of the exterior control panel, sometimes with a hidden vent (usually hidden under the area of the control panel extruded so you may grasp the door to open it.

Should there be a little water in bottom of dishwasher?

If the amount of water left in your dishwasher after a cycle is no more than two cups, then this is normal. Usually the appliance remains wet after a cycle due to the condensation drying principle which causes water droplets in the tub – they are indeed desirable here.

How long do dishwashers last?

Average Lifespan of Dishwashers

According to reputed appliance repair technicians and manufacturers, the average home dishwasher lasts between 10 to 15 years with regular use and proper maintenance. Even an appliance from the best dishwasher brands will only last 15 to 20 years at most.

How do I add an air gap to my dishwasher?

Step 1: Preparation
  1. Remove the kits from the air gap, including decorative cap (A), top cover nut (B), top retainer nut (C), and the counter gasket (D) while remain the bottom retainer nut (E) on the air gap.
  2. Adjust the bottom retainer nut (E) for sink thickness. ...
  3. Install the air gap through the hole in your sink.

Does dishwasher installation include air gap?

No, the air gap is not included with either the dishwasher or the installation kit. The air gap can be found in most hardware stores that carry appliances. It is not very expensive, and cheaper than if you get it from your plumber or installer. This is typical with most dishwasher brands.

What are the rules for air gaps?

* An air gap between the water supply inlet and the flood level rim of the plumbing fixture, equipment, or nonfood equipment shall be at least twice the diameter of the water supply inlet and may not be less than 25 mm (1 inch).

How do you know if you need an air gap?

A drain hose that is connected to house plumbing lower than 20 inches above the floor will need an air gap. Check your local codes and requirements. Unless mandated, dishwasher air gaps are not always recommended by professionals.

What is the air gap for dummies?

An air gap involves physically isolating a computer or network from other networks to prevent unauthorized access and data breaches. This method creates a literal "air gap" between the secured network and any other unsecured networks.

What is the difference between air gap and non air gap?

The main difference between an air-gap and non-air gap faucet is that a non-air gap faucet does not have a physical siphon break from the Reverse Osmosis (RO) system itself and the sink drain. Non-air gap faucets are quieter (less gurgling noise) than the air gap system.

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