We had a contractor that we use all the time install a garbage disposal and an air gap. Previously the home builder had hooked the dishwasher directly to the drain which I understand is not proper.

After installing the air gap, water leaks out onto the counter when running the dishwasher. It happens consistently. The thing is the dishwasher and all the piping are basically brand new. We have tried all the obvious things:

- The line isnt clogged or kinked, which is the assumed answer any time this usually happens

- The knockout plug on the disposal was removed properly

Our contractor and his father who has been a plumber for 30 years are both stumped. Everything I find online assumes the problem is one of the above.

Is it possible that the dishwasher is just draining with an absurd amount of pressure and is there a way to adjust this? It's a Blomberg 51600 which I have never heard of but its apparently pretty common.