air gap device

I understand the purpose of an air gap is to prevent dirty water from flowing back to the dishwasher. My air gap is connected to the garbage disposal and dishwasher underneath the sink. ? is , i see water come out of it is this suppose to happen or not?. i always thought it was normal but i am told now it is because there is something blocking it. what is the truth anyway.

This is not supposed to happen. The air gap is not an overflow device. There is a blockage causing water to escape throught the air gap. Most often the blockage is in the hose attached to the disposal.

thanks Shane

Although it does also serve as an emergency overflow device, but when you see water coming out of it, that means the main drainage line is blocked.

It’s interesting that I find this problem most often in new construction. Seems the plumbers, for some strange reason, don’t know to remove the knockout in the disposal.