The longer the hose before it gets to the air gap, just means that much more that will drain back to the dishwasher.
Most dishwashers come with a four foot drain hose aprox.
I have a new Whirlpool dishwasher that I can't get to work, machine doesn't finish the cycle and ends up canceling and pumping the water out.
After having two different service techs look at it the second guy told me the drain is siphoning water and I need to install an air gap.
I've installed the air gap but the problem remains, I used clear tubing to connect the air gap to the drain and I can see the water running through.
This is not a typical dishwasher installation, the machine is across the room from the sink, the previous owner built a spot for a dishwasher with a drain pipe built into the wall that drains into the basement floor drain. The drain pipe is approximately 28" above the floor and the dishwasher drain hose connects to the air gap approximately 34" above the floor.
I'm really at a loss how it can siphon water so high and even with the air gap installed. Is there an adjustment to be made on the air gap or could it just be faulty?
I'd appreciate any help I can get with this.
Siphons do NOT operate spontaneously. Something has to get water flowing to fill the inverted "U" and then the siphon will function on its own. During the fill cycle there is nothing flowing into the drain so a siphon cannot begin. BUT, if the drain system is in the basement, then the water will drain out as fast as it comes in, and that would cause your problem.