 It goes up, and then it goes down. It needs air. It's like the vent on the back of a one-gallon gas can. You know, blurp, blurp, blurp. You hit that vent, and it goes, you know, everything goes right. So I think what's happening is there's probably a problem with one of the vents up top where there's some debris in it restricting the airflow. It sucks the water out of that J-bend, and it's getting the airflow there that it should be getting from the, you know, outdoors on top of the roof.