EDIT: Delta/Brizo is sending a new cartridge, and we will try that. Thanks for all the assistance.

Plumbers, please help! I had my main bathroom redone. I hired a reputable contractor. We bought our fixtures at a plumbing supply store. After talking to them, we liked the idea of the thermostatic shower, as we had some small issues with the temperature changing when flushing, but there's only two of us, so no big deal. Now, however, with this Brizo controller, we can't get a hot shower and a cold shower. We can only get warm and cool. If we have the plumber turn down the cold, the hot gets less hot. If we want it hot, we can only get to warm on the cold side. Is this how it is supposed to work? NO ONE TOLD US THIS. I hate this controller right now, and if I can't get this fixed, I don't know what to do.