"ashroyer" wrote in message
...

I'm totally re-doing my bathroom and shower. I tore out the old shower
2 months ago, re-routed the plumbing, and capped off the pipes. At this
point I am ready to install my new shower mixing valve but I don't know
which pipe is hot and which is cold.

Are there any tricks to identify which is which short of uncapping the
pipes and letting the water fly??

You just look where you wrote on them with the magic marker.

Run the hot water in the nearest room that has hot water. It may warm the
pipe enough that you can feel a difference between the two. If you followed
normal conventions, the pipe on the left facing the point of use is the hot.