What is a Dishwasher High Loop and Why do you Need

During a home check, finding a dishwasher drain line without a “high loop” is common. If you need to figure out this, think of a picture (Figure 1). So, what’s a high loop? And why does your dishwasher need it? Don’t worry; fixing it is usually simple. Let’s talk about it.

What is a high loop? 

A high loop is when the dishwasher’s drain hose rises before connecting to the sink’s drain. You can see how it looks in Figure 2. It’s like making the hose climb a small hill under the kitchen sink. To make it work best, the hose should be tied up close to the bottom of the cabinet.

The hose should connect to the sink pipe before the curved part is called the P-trap. It’s important not to connect it to a garbage disposal because it might send dirty water back into the dishwasher.

Why do we use a high loop?

A high loop stops dirty sink water from going back into your dishwasher. If you don’t have this loop, your dishwasher might have unwanted water at its bottom. The loop makes it hard for water to return to the dishwasher because it has to go uphill.

How to Set Up a High Loop for Your Dishwasher?

To set up a high loop, close it to the bottom of the counter. This helps it work best. The hose should connect to the sink drain before the curved part (P-trap). Please don’t put it on or after this curve. Use a zip tie to keep it in place. The top part of the loop should be at least 32 inches off the floor. If you can’t do this, think about other solutions.

Is the High Loop the Best Choice for Your Dishwasher?

High loops are helpful, but there might be better options for some. They can’t always stop dirty water from returning to the dishwasher, especially if there’s a big drop in water pressure. Also, if you can’t make the loop’s top part 32 inches above the floor, it might be better to get an air gap.

Air Gaps Explained

Air gaps are a better choice for your dishwasher compared to high loops. They’re placed above the sink to stop dirty water from returning to the dishwasher. Air gaps create space between the dishwasher hose and the garbage disposal so water can’t pass through. While most of the air gap is under the sink, you’ll see a small part next to the faucet. If the drain gets blocked, the air gap lets the extra water into the sink. If you see water leaking from your air gap, it means there’s a blockage in your drain pipes.

Should I get an air gap?

An air gap is a device that stops water from going backward even more effectively than a high loop. Installing it takes more effort, though. Some local rules might ask you to have an air gap, but many places are okay with just a high loop. The gap introduces air, so water can’t flow back into the dishwasher.

It’s placed near the sink and connects to the hose below. Most new sinks do fine with only a high loop. But if you’re having problems with water going back into your dishwasher, ask a plumber about adding an air gap.

What is a high loop on a dishwasher?

A high loop is when the dishwasher’s drain hose is elevated, making a ‘loop’ before connecting to the sink drain.

Should a dishwasher have a high loop?

Yes, a high loop helps prevent wastewater from the sink from flowing back into the dishwasher.

Is a high-loop dishwasher better than an air gap?

No, while a high loop is effective, an air gap is a more foolproof method to prevent backflow into the dishwasher.

What if a dishwasher does not have a high loop?

Without a high loop, there’s a risk of dirty water from the sink flowing back into the dishwasher, which could lead to cleanliness and operational issues.