Hi - I have always had a mixer shower over the bath, which has worked perfectly, with no issues regarding flow or pressure. As the diverter had broken and the unit was old, I today had it replaced by a plumber. Now it would seem that the flow is reduced. The pressure seems fine when I use the mixer tap in the bath, but when I switch it to shower the flow is reduced. With my old one, the flow was ok but a little low when I had hot water only turned on, but when I added cold, this added substantially to the flow. It seems with this new one, there is no difference to the flow when I add more cold water - it stays exactly the same. Does anyone know what could be the problem? (It is a gravity fed system).