Hi... I have a problem I think... I have No hot water in my bathroom at all, When I turn on the hot water tap for the tub nothing comes out and the same for my bathroom sink, However when I leave the bathtub tap on and turn the cold water on from my sink that tub runs water as does the sink and when I turn the sink off the tub shuts off too?

What kind of problem is this?

Snoopy, have you had any plumbing work done? Does the tub have a shower? What brand of fixtures to you have?