Dear all, I have a combi boiler in my house. The tendency for the flow
rate in the shower upstairs to be be reduced when a hot tap is turned
on downstairs really bothers me. Presumably, the water is
preferentially drawn by the downstairs water outlets because of the
pressure differential. So, am I correct in thinking that a sensible
solution is to fit a pressure reducing valve to the downstairs hot
water supply to the taps in order to balance the resistance to flow of
up and downstairs? Obviously the flow rate in the shower would still
reduce when a downstairs tap is turned on, but am I correct in
thinking that the effect should be less marked?

Thanks, Jim.