I just installed the Turbo Spin dual shower head in the upstairs shower and it only gets lukewarm... I cannot see that there is any type of control setting on the shower head itself... the downstairs shower is getting water that goes hot... Is there something I am missing... I am about to install the same dual shower head downstairs and I don't want the same result.

Remove new shower head and run water w/o it. See if you get hot water again...