I work in a 10 story building which has low water pressure in the hot water supply, there are only circulation pumps on the return side of this system. Now I know that the galvanized risers are probably pretty clogged with deposits. So my question is should there be pumps for the feed side too and I imagine they do but what size motor and impeller would you suggest they currently have 1/16 hp and 3" impelers for the return pumps should the feeds be the same or bigger?