I'm trying to accomplish the same thing, and I can't seem to get it working either.
By "dimension anchor value" you mean the "Dimension Anchor Elevation Value for Structures" option under Pipe Networks>Edit Feature Settings?
Because no matter what I do, as soon as I set that line (or the text) to Structure Dimension it dissappears.
My profile goes up to 1075, so I set that to 1075, 1070, or whatever. Can't seem to get it working.