I am trying to run a water line for my fridge. I put the saddle valve into the sink cold water copper pipe. That seemed to work fine - no link from the valve. But, when I screw the plastic tubing into the fridge, and then turn on the water, the plastic tube pops out of one end or the other when the water reaches full pressure. Only takes a few seconds for it to pop out.

Each end of the tube connection has a copper insert for the plastic tube, and then a copper nut that the tube goes through. I run the plastic tube through the nut through the tube, then put the insert in, and then screw it on as tight as I can with a wrench. No dice.

What am I doing wrong?

2 Answers 2


Make sure that the pipe is inserted into the valve as far as it will go before you tighten the compression fitting - it would only slip out if not properly tightened against the ferrule.

Two other recommendations:

  1. Get rid of the piercing saddle valve and install a ball valve (1/4 turn) that has either a compression fitting or is soldered in place.
  2. Scrap the plastic pipe and pick up some 1/4" flexible copper supply line.

The first is more important. The piercing values are usually not to code. They can be difficult to turn off (not good in the event of a leak), and often the pierce does not make a large enough of a hole for adequate water flow, which can result in ice making problems and slow water dispensing.

  • I definitely agree that I should've not gone with the saddle valve, but I am not skilled enough at plumbing (yet) to be replacing valves. If I have to I will bring in a plumber to make the changes you suggest. Commented May 1, 2012 at 11:45

I ended up heading back to the big box hardware store and the guy in the plumbing section helped me out. For a few bucks, he sold me some different compression nuts and inserts that he said worked better. In addition, he told me to hold the tube while tightening the nut so that it doesn't get pushed out by the compression. After following those steps, everything worked without leaks.


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