📖 GLOSSARY · CONCEPT
What is a high loop?
A rise in the drain hose fitted up under the counter that stops sink water siphoning back into the dishwasher.
The drain hose must rise to just under the countertop before dropping to the disposal or standpipe. Without that high point, dirty sink water can siphon backwards into the tub — which shows up as a dishwasher that smells, or one that mysteriously has water in the bottom between cycles. Some jurisdictions require a physical air gap on the counter instead. A missing high loop is an installation fault rather than a broken part, and it is very common.
Where you’ll meet it
Repairs that involve high loop
Related terms
DON’T WANT TO DIY IT?
Find a dishwasher repair pro near you.
Browse verified independent appliance repair companies by city — ratings, hours, and phone numbers, no middleman.