Okay, I recently went to a dual fan set up.....they kick on just fine, however I believe that was just one of my issues. I finally cranked her up (started as normal), but upon shut down I could feel a little bit of water on the bottom hose as I squeezed it but the top hose just seemed full of air. I put a squeeze on it and heard or felt no water at all. Wouldn't this indicate a lack of circulation? I turned it off and heard a loud hiss until air was depleted. Sound like a water pump to you guys?