Hi my name is Brian. I have a Inground pool which I purchases in 1985 and I had the vinyl liner replaced about 3 years ago, for some reason the liner does not want to stay locked into the coping in different ares of the pool now. What causes this to happen considering I never had this problem with the first liner ? I now am not able to put the sections back in the coping. I have asked around and have been told to do different things like boil water and pour it on the on the sections in question so they can be stretched back in place. The problem is what is causing the liner to come out in the first place. NO one is willing to answer that question.

Sounds like the liner is not right for your pool or is just a bit off. Did you buy the liner from the same place/manufacturer you got your pool from?

Go to your local pool store/internet and get something called liner lock and install it, put the liner back into the groove where it normally sits and the liner lock gets pushed down into the same groove so that when the pool fills back up and the liner tries to pull back out it pulls against the liner lock and tightens itself down preventing it from pulling out. As to why it is pulling out it could be that the liner is slightly to small for the pool size and when it gets full of water it may not have enough slack to settle out and instead pulls out of the track, or it could be that the sand bed/ground underneath the pool should be raised due to erosion taking away some of the height.