I had my bathroom upgraded last year and it looks really nice.Before i had a shower unit over the bath and it worked really well with plenty of pressure,it worked so the hot water coming into it came of the hot water tank and the cold water came from the tank in the loft.The bathroom was upgraded and i got a powerfull pump put next to the hot water tank the pump pumps both the hot and cold water to the bathroom mixer and then to the shower head.The pump is a negative head pump of approx 2.2bar pressure,we have had the pipe work altered that many times and the problem still seems to be there.The bathroom is about 3metres away,the problem seems to be not very good flow.The pipe work has been checked out by so called experts and the pressure going to the pump has been checked and is fine.I think it is because it is the pipe work,it goes down to the pump and then goes up into the loft near the cold water storage tank and then across to the bathroom and then to the mixer half way down the wall and then to the shower head.I think it loses to much pressure going up to the loft and then down to the shower.I am now thinking of putting the pump directly under the bath and putting the pipe work under the floor,so the pump is directly under the mixer so that the pump is only driving upto the shower head.Does anybody think this will work.