Why would my upstairs bathroom have no hot water? Water gets semi warm, but not hot. Both bathrooms downstairs and Kitchen have very hot water...

What fixtures do you have upstairs and are they all luke warm?

They are Valley. And after further review, realize that the fixtures are in backwards. I appreciate the answer, and am sure you've heard this one before. From a previous home, I know that Valley is no longer - and I'm going to replace these in the whole house, any suggestions on brand?