Which states require a dishwasher air gap?

Author: Nina Sauer III  |  Last update: Tuesday, May 6, 2025

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

Is it code to have an air gap for dishwasher?

Most states even enforce plumbing codes that require dishwasher air gap installation in residential and commercial sinks. If your drain hose is connected to house plumbing lower than 20 inches above subfloor or floor you will need to use an air gap.

Do all dishwashers require 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.

Does Texas require an air gap for a dishwasher?

Appliances must have air gaps as required for connections to the sewerage system. Venting must assure a rapid flow of wastewater in the sewage system.

Are dishwasher air gaps required in Nevada?

PLUMBING AND MECHANICAL: 1. The water supply for dishwashers shall be protected by an air gap or integral backflow preventer.

Dishwasher Air Gap-Do You Need One?

What states require an air gap for a dishwasher?

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

What is the alternative to the dishwasher air gap?

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.

Do you need a dishwasher air gap in Wisconsin?

An air gap device is not used in all dishwasher installations and is not provided with the Cove Dishwasher. Air gap requirements vary by state. For example, Wisconsin requires an air gap above or below the sink.

What is the air gap in California?

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 one inch.

Is a dishwasher air gap required in Minnesota?

No domestic dishwashing machine shall be directly connected to a drainage system or food waste disposer without the use of an approved dishwasher air gap fitting on the discharge side of the dishwashing machine or run the discharge line as high as possible under the countertop, securely fastened.

Do Whirlpool dishwashers require an air gap?

It is recommended that the drain line be connected to your house plumbing using a drain air-gap (Part No. 300096) available through your Whirlpool dealer. NOTE: Some other brands of drain air-gaps restrict water flow excessively and can result in incomplete drain.

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.

Does a Bosch dishwasher require an air gap?

The Bosch Instruction manual states: “If no air gap is used and the drain line is run into a sink or disposer, the drain line must be elevated to a point higher than the highest water level of the sink to prevent back siphoning into the dishwasher.”

What is the air gap on a dishwasher in Los Angeles?

It's called an “Air Gap.” Basically, it is to prevent dirty and contaminated water from backing up into the water supply through the dishwasher. It's required by code in California but some people bypass this requirement and have something called a “High Loop” under their sink.

Does a commercial dishwasher need an air gap?

Not all commercial dishwashers are fitted with a Class 'A' Air Gap as standard. However, as we previously mentioned, an Air Gap is a legal requirement for dishwashers within commercial kitchens and we, therefore, recommend checking the dishwasher's specification before purchasing.

Does a Thermador dishwasher need an air gap?

If local ordinance requires an air gap, the dishwasher will need to be installed with one. But otherwise, an air gap is not required.

What states require air gaps?

They are required by Code in only a handful of states; according to the thread, California, Texas, Washington, Nevada and maybe a couple others. The air gap is to prevent dirty water from your dishwasher from flowing back into the dishwasher to re-dirty the dishes.

What is air gap violation?

An air gap is a security measure that involves isolating a computer or network and preventing it from establishing an external connection. An air-gapped computer is physically segregated and incapable of connecting wirelessly or physically with other computers or network devices.

Where is an air gap required?

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.

Does California require an air gap?

Everything in Plumbing can be repaired or replaced.

there are a few companies that make an air gap device that mounts under the cabinet. As you already know, it is required by California Plumbing Code. The only way around it would be to run the drain line through the wall to a standpipe outside the house.

Does the Wisconsin code require an air gap?

All indirect waste piping and all local waste piping shall discharge by means of an air-gap or air-break into a receptor. (a) Air-gap installation. The installation of an air gap shall conform to any of the following requirements: SPS 382.33(7)(a)1.

How much does a dishwasher air gap cost?

While those brands are the most popular overall, you will also find a great assortment from KOHLER, Oatey and Keeney. How much does a Air Gap cost? A typical price for a Air Gap is $25 but can range from approximately $6 to $39.

Does a Samsung dishwasher need an air gap?

Ensure the dishwasher's drain hose connected to the sink is not compressed, twisted, or damaged. In some regions, adherence to local regulations requires an air gap or a high loop in the hose to prevent backflow and guarantee efficient drainage.

What if my sink doesn't have an air gap hole?

If your sink lacks an available hole for installing an air gap, a plumber can usually drill an opening where needed.

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