I had t0 replace a hot water non emersion cylinder, it was like for like with the previous one. However for some reason this has resulted in reduced hot water pressure to the mixer shower meaning its now impossible to shower. THe Plumber said it could be lime scale in the old mixer unit so I replaced it but the flow from the shower is no better. The Plummer returned and checked the cold water supply to the cycinder and the gate valve and said there was no problem. He suggested i install a pump. The connection pipes to the mixer unit have not changed and the distance from the hot water cylinder outlet to the shower is 35cm. Is there anything else I can do before buying a pump and getting it fitted? If a pump is the only solutuion(I dontwant an Electric Shower)is there any particular brand/type that is better and anything i need to know?