Clack Drain Line Leaking at Polytube Elbow/Nut (new unit)

[meerkat]

I have a new Clack WS1EE unit. Install went fine except for the drain line. The system came with a 5/8 OD, 1/2 ID poly drain line, polytube insert, and 3/4 drain elbow nut. I put the insert into the end of the tube. I was able to insert it fully. I slid the tube all the way into the elbow as far as it would go, then tightened down the nut. I tested the Regen cycle and the drain line nut is spurting out water. When I look inside the drain elbow, it's just plastic. The polytube insert rests inside the elbow, and the nut just kind of holds it there. I don't see how this plastic-on-plastic connection would ever be water tight. My old softener had a compression ring that sealed the drain connection. As a temporary measure, I placed an O-ring around the drain line between the elbow and the nut, and it actually stopped the leak. I know this isn't the proper fix, so I'm looking for suggestions as to why my drain line is leaking, and what I can do about it.

 

[ditttohead]

If you are using the supplied nut, that is designed for PX tubing,. not soft tubing.

 

[Sponsor]

 

[meerkat]

Yes, it's the nut that says POLYTUBE INSERT ONLY. It's a black tubing that's not all that soft. It's quite hard, actually. It came rolled up in a coil. When you say PX tubing, are you referring to PEX? If so, how is one supposed to connect the black tubing I got with the unit?