High Loop (Drain Hose)
A loop in the dishwasher drain hose installed above the level of the disposal or sink to prevent backflow.
Definition
A high loop is a loop in the dishwasher drain hose installed above the under-counter level of the disposal inlet or sink connection, preventing wastewater from siphoning back into the dishwasher. Most local plumbing codes require either a high loop or a separate air gap fitting on the countertop. The high loop is the simpler installation and works well in residential applications. Standing water in the dishwasher tub at the end of cycles often indicates a high loop that has slipped — pull the dishwasher out and re-route the hose against the underside of the countertop.
Where this term appears
High Loop (Drain Hose) comes up in product spec sheets, service reports, and troubleshooting documentation across most major appliance brands. If you encountered it in a manual or a service description and want context for how it fits into the larger picture, the related articles in the sidebar drill into the practical details. The glossary as a whole is intended as a quick lookup reference; for a deep dive on any specific topic, jump to the related buying guide or troubleshooting article.