Hi was looking for bit of help with secon day pump. Was asked to replace a secondart pump the other day in a hotel which I done. After fitting the new pump when the pump is flowing the pressure decreases quite considerably, the pressure drops even more depending on which speed the pump is set at, I can't remember how it's working whether if you drop from speed 3 to speed one the pressure gets higher or lower and vise-versa. It gets to a point that the pressure loss at taps results in no water coming out at all. The cylinder is feedin one floor. I have had to switch pump off at moment as pressure is ok without it on at moment. Only thing I can think of is it is ducking too much water through circuit and not getting a chance at branches. Any help would be appreciated