I remember from the show that the kids are live actors that are transported into another world where they use CGI for that side, or at least I think it is CGI. It is not Code Lyoko or ReBoot: The Guardian Code, but it is like those shows. Another thing I remember from the show is a red wheel on a pipe that I think has some importance in going to the other world.
1 Answer
You might be thinking of Zixx (2004-2009).
It involves teens travelling back & forth between the real world (presented in live-action) and a virtual world (presented in CGI), and the portal between worlds is opened by twisting a circular valve on a pipe.