What is a high loop? A high loop is when the dishwasher drain is elevated right before its connection to the kitchen sink drain. The drain hose is secured near the top of the sink in some fashion (could be as easy as using a zip tie to secure it).

Why do dishwashers need a high loop?

Bosch: The high loop in the drain hose of your dishwasher is to keep water from settling in the hose if it were hanging down any lower or horizontally. This keeps the drain hose dried out and keeps any odors from backing up into the dishwasher.

What is dishwasher high loop?

A high loop is a method of backflow prevention where the drain line runs from the dishwasher to the highest point beneath the sink. The loop is affixed to the underside of the counter with a bracket, then drains down into the garbage disposal or sink drain.