Get matched with top dishwasher installation pros in Ellendale, DE

Yes, a dishwasher needs an air gap to prevent backflow. Additionally, in many locations, air gaps or another measure to prevent backflow are required for building code compliance. There are alternatives to an air gap, like a Studor vent or a loop and trap design, but an air gap is the simplest and most popular solution.  

When a dishwasher discharges its wastewater, it uses a pump to quickly move a lot of water. If anything in the drain line or the garbage disposal impedes the high volume of water, it will back up into the sink through the drain or the garbage disposal. Following regular dishwasher maintenance tips like clearing clogs, keeping them cleared, and occasionally running the disposal will eliminate the problem.

To create a siphon break and remove any chance of dirty sink water or water that backs up into the sink from getting into your dishwasher, your dishwasher drain hose needs to have a high loop or an air gap device as part of its installation. All building codes require at least a high loop. In many places, it’s necessary to install an air gap device to meet the code.

Not all dishwashers are 60cm wide, but that tends to be the most common size. 60cm translates into roughly 24 inches, with most home dishwashers being between 22 and 24 inches wide. There aren’t metrics available but it’s been our experience that over 90% of household dishwashers in North America are around 24 inches wide by 24 inches tall.