RO DI problem

So I bought a RO DI unit off craigslist and something isn't right, I checked again and again and all the tubes are on correctly but the only place water is coming out is the product water tube, and barely a dribble out of the waste water tube. What could this be? I tried to unscrew the membrane vessel and wiggle that but it wont even budge a little. Another thing is that it didn't come with a pressure gauge but there was a hole for one, so I bought one and replaced it so there isn't water coming out of that hole anymore but there is still no water coming out of the waste water tube and all of it is coming out the product water tube.


Thanks!


--Miles

 

By the way, it's a Kent Marine Maxxima Hi-S system.

Thanks everyone!


--Miles

 

I would check to make sure you're not mixing up which tube is which. Then, I would check to make sure there's a flow restrictor in the waste water line.

Here's a diagram of how it should be plumbed in, on page 4.

 

Pay particular attention to that "End View" diagram, this is where people commonly mess up by getting the line placement wrong.
The fitting closest to the center is always the permeate or treated water and the one closest to the outside edge is the brine or waste.

You can test this with a TDS meter, obviously the treated will have lower TDS and the waste should be 20 to 25% higher TDS than the tap water.