My dishwasher is not directly next to the sink, there is a corner cabinet and another cabinet that separate the two. Therefore I'm planning on draining the dishwasher through the floor into the basement directly into the drain pipe there.
My instructions say I need at least 18" loop or an air gap in order for the dishwasher to operate properly. Is this only if I'm draining "upwards" to the sink? Or do I still need that when draining straight downhill to the drain in the basement.
What is the purpose of the air gap or loop? Is it some sort of pressure thing with the pump? Or is it simply to make sure dirty water doesn't come back into the dishwasher? If it's to eliminate dirty water, could I simply put a one way check valve in the drain line to keep it from back flushing?
I asked these questions on another plumbing forum and all I got was smartalec remarks and was told that I needed to hire a professional plumber. I want to do the job right, but I also want to understand what it is that I'm actually trying to accomplish.