What Is a High Loop Dishwasher and Why Should You Use It?

When your dishwasher drain is elevated before connecting to the kitchen sink drain, it is called a high loop. The drain line is installed with a proper loop. Moreover, it is raised and connected to the underside of your countertop or under the cabinet. In short, it looks like an upside-down P-trap that you can find under the kitchen sink.

high loop

Why is a High Loop needed for a dishwasher?

Every dishwasher drain usually falls into the garbage disposal. It lays horizontally at the bottom of the kitchen cabinet. If you don’t install a high loop, dirty water from the dishwasher will be collected in the drain line. As a result, it can flow back to the dishwasher. Thus, wastewater will enter your dishwasher and causes odor and disturb your cleaning process.

That’s why; using a high loop will provide an elevation to the drain hose. So, the dirty water from the dishwasher will never flow back and will drain out properly.

How to install a High Loop?

There are two easiest ways to install a high loop for your dishwasher. You can opt for one of them to provide elevation to your dishwasher drain hose. These methods are:

  • Install a bracket
  • Use a zip-tie

Install a bracket

Installation of a high loop with a bracket is easy, and you don’t have to use any tools for this method. All you need for this is a high drain loop bracket and four pieces of 3M VHB tape. Follow the given procedure to install the high loop.

  • First, you have to clean and dry the area under the sink to perform the installation process.
  • You have to apply the bracket as high as possible. It will help provide enough space for the drain hose to make a loop at the top of the bracket.
  • Peel off the white wrapping of VHB tape.
  • Apply the four pieces one by one at the corners of the drain loop bracket.
  • Press the tape for at least 30 seconds.
  • Now peel the red wrapping of the tape.
  • Place the bracket under the sink area that you have previously prepared.
  • Press and hold the bracket firmly for at least 30 seconds.
  • Now, you have to make a loop at the top of the drain hose and push it into both sides of the bracket.

You can install a high loop easily to your dishwasher by this method without using any tools.

Use a zip-tie

For a zip-tie method for high loop installation, your drain line should be installed at the house side of your P-trap under your kitchen sink. If the drain line is not present here, the dirty water will flow back, and your dishwasher will smell like sewage. Thus, at the time of dishwasher installation, always install a drain line at the housing side of your P-trap.

  • Get a zip tie to create a high loop on the drain line.
  • Access the drain line and tie the drain line with P-trap by using a zip-tie.
  • Take screws to install a hanging tab under the sink at the wall for creating a high loop.
  • Now, hang the zip-tied drain line to this hanging tab.
  • Make a high loop as high as possible for better draining.

Hanging drain line

Bottom Line…

You should check the dishwasher’s manual before creating a high loop. Because these days, dishwashers come with an in-built high loop, so you don’t have to install a new one.

Frequently Asked Questions

1. Is a high loop necessary for a dishwasher?

The high loop is necessary for a dishwasher for two main reasons.

  • During the drain cycle, a high loop ensures proper drainage.
  • It prevents the backflow of contaminated water from garbage disposal to the dishwasher.

2. What does a high loop look like?

The high loop under the kitchen sink looks like an upside-down P-trap. The drain line is elevated with a high loop and connected under the cabinet or countertop.

3. Which is better, an air gap or a high loop for a dishwasher?

Although a high loop works perfectly for draining a dishwasher but is not as reliable as an air gap. Both air gap and high loop prevent the backflow of dirty water into the dishwasher. The air gap prevents siphoning. A high loop can’t prevent it as efficiently as an air gap does.


  • Stephen Powers

    Appliance repair guy from Washington. I am majorly experienced in dishwashers, water filters and refrigerators, AMA on my twitter account.

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