Dishwasher air gap alternatives

Dishwasher air gap alternatives. If you want to bring a dishwasher to your kitchen, you need to know about air gap alternatives too.

An air gap prevents the drain water from backflow and keeps the dishwasher protected from contamination. While installing the dishwasher, you should be warned about a needy air gap.

There are some good alternatives to the air gap, that proved handy in stopping the wastewater from re-entering the dishwasher.

As recommended by many buildings’ codes, you must have an air gap to be installed for the dishwasher. There are three very useful airgap alternatives, there are a high loop, a standpipe and the third one is a check valve. Keep reading, we will explore each one in detail.

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We are going to discuss three different methods to prevent water backflow, these are likely a high loop, check valve, and standpipe.

Think of a High loop

A high loop is the most commonly used alternative for dishwasher air gap and it is the ideal way to control the water backflow.

A high loop is a unique configuration of a drain hose where the line is installed underneath the sink level and it takes the line up above the water level. You can either link it to the drain or with the garbage disposal. It works on the basic principle of physics and gravity.

Adding this alternative helps to prevent the water backflow to the dishwasher. The best thing about the high loop is that it does not require any special equipment or parts. The only component you will require is a set of brackets or a set of hooks to keep the drain hose in place.

Check valve as an alternative

Think of the check valve as another air gas alternative for dishwashers. A check valve is a hardware component that makes sure water or ay liquid flows in one direction only.

While using the check valve no need for any extra hardware to be installed in the kitchen area, it easily handles water backflow and prevents drain water from getting in the dishwasher.

Most dishwashers have a built-in flap check valve located near the drain hose. Avoid using check valve as the priority, it can be used when there is no other option.

Installing a Standpipe

Think of a standpipe as a long vertical pipe that can be considered as a possible alternative for the air gap, it is a kind of long pipe mostly located at the P-trap portion of the plumbing unit. Consider the diameter of around two inches and it will help in easy ventilation of the dishwasher.

Another fair benefit of the standpipe is that it also speeds up draining alongside the air gap. Adding a second standpipe under the sink helps in preventing backflow and keeps the dishwasher ventilated.

Although a standpipe is not the best choice as an air gap alternative, it requires a lot of plumbing fatigues to be followed, and it is a costly process.


There are three commonly used fair alternatives to the dishwasher air gap, choosing the right one depends on the building codes. Ask your plumbing staff which would be the best among these. In my opinion, the high loop is the best among these three as it does not involve any extra components or costs.

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