RO/DI Help

[Millepora_Maniac]

Hi everyone, I prchased a four stage ro/di today from J and L, I'ts called the AQUA FX barracuda. My drainage line is flowing fast and my product line isn't putting out anything. What did I do wrong? when I plug the drainage with my finger, the DI starts to fill. but without plugging the end, I get no flow through the system, anyone care to help!! Thanks - Ken