I have never had the line inside the fridge freeze up in any of my fridges ice makers or no leaks. The line should be empty after water is dispensed for ice making. Maybe it's the model of fridge that has the problem. I do know a metal line is much better then plastic tubing coming from the sink hook up. Most new fridges have a built in filter. We by passed that and put a filter in the metal line going to the ice/water. It does a better job and much cheaper to replace. $12 vs $49 per filter.