What is the proper way to plumb a dishwasher’s drain line?
And what is the role of the airgap? Is it essential is all situations?
My current vision: connect dishwasher drain with flex rubber-type hose to the kitchen sink tail piece (tail piece has a modified “T” whereby the rubber hose can be hose clamped)
Is this the finished produce?
Is an airgap necessary in this scenario?
What is the role/function of an airgap?
Thanks.
Replies
Air gap is required by some local codes, but not required by others if the DW doesn't spec the gap as required (and most don't).
The air gap supposedly prevents water from flowing from the drain into the DW if the drain line gets clogged. In practice, if the drain line is routed as high as possible up against the bottom of the countertop (and usually there's a loop of the drain line in the DW itself that does this), then no backflow can occur so long as someone doesn't fill the sink nearly to the rim while the drain line is clogged.
What Dan said, however I'll add that here in NC air gaps are not installed on dish washers any more. You see them on older homes. BIs are strict about having the DW drain attached to the bottom of the counter top though.
Code enforcement/requirements that vary are weird. Here in CA the air gap is required by law. I and my customers hate the things. The high loop is a better solution all around, IMO.Bill
Thanks for the input.I like the scenario whereby the flex drain line is simply attached to the countertop (underneath).In this application, the DW is around the corner (about 6LF) from the sink drain. The flex drain line will need an extension. Planned to just use rubber hose. How can I keep the rubber hose from collapsing when making the 180 degree loop under the countertop?
> How can I keep the rubber hose from collapsing when making the 180 degree loop under the countertop?Use oversized plastic (conduit or DWV) elbows -- slide the hose inside.
People never lie so much as before an election, during a war, or after a hunt. --Otto von Bismarck
Did dishwasher with an air gap a couple years ago. The dishwasher was around the corner and three cabinets away from sink. The instrutions said if the flex drain ran below floor level it should be air gapped. It made more sense to extend drain and water line in basement, rather than route through cabinets. Worked fine and the cute home owner told me she loved me.
The air gap is a safety device as is the high loop off the dishwasher. The idea is to prevent any siphon action that could suck drain water back into the machine. Both will work, but the local codes dictate what one you should use, this debate has been going on since the beginning of time. Bottom line is if you hook up the drain by the manufactors instructions you should not have probs. Luck.
"If all else fails, read the directions"