Could anyone give me some advise? I fitted a mains shower. Both hot and cold pipes are 22mm. The hot water comes from a hot water tank. When both the hot & cold are running from the tap, before the shower is activated, the temp is just right, but, as soon as the shower is activated the shower is colder and I have to adjust the cold tap by miniscule amounts until the correct temp is had. If the cold tap is touched just slightly too much the water is too hot. Also the cold gushes out of the tap faster than the hot, but in the sink, where the pipes are both 15mm, the pressure on the 2 is about the same. Could this be due to a faulty tap, do you think? Or is it something to do with the water pressure? Help!