Thank you for your reply .
Yes I have a pipe as seen below.

I filled then the volume with fluid with fill tool.
My Boundary conditions: inlet: velocity: 0.1 m/s T=400K
outlet: p=0
inner wall (red lines below): T= 600K

As I said I just ran 1 iteration to see if it worked with the temperature boundary condition at the wall. I plotted the temperature contours at the inner wall. I saw that there was a different temperature than assigned. Outcome is 400K at the walls rather than 600K.