It has to be as short as possible with no dips or fittings between it and the disposer. Four feet and an elbow would probably create too much resistance for the water to flow properly.
: Water from my dishwasher was coming through the air trap on a regular basis. I thought there was
: some blockage, but when I looked I found the Hose from the air trap to the garbage disposal was
: flattened out from a too sharp turn. It looks like this was blocking the flow back into the air gap.
: I replaced the air trap and the hose from trap to disposal. A 2 foot hose was too short because the
: turn to hook it up was flattening out the hose. I got another 2 foot hose and an ell joint and hooked them
: up. I ran the dishwasher and water still came out of the air gap.
: Does the hose need to be shorter?
: Is there any special way to install the air gap?
: Do I have a different problem?