Large house with combi boiler. Water pressure at outside tap 1.8bar, nearby utility room tap has very good pressure and flow. Kitchen tap about 8m away has less flow, from combi going up to cieling then down to kitchen taps. Bathroom taps with shower, 1.5bar reasonable flow, situated slightly further away from boiler than kitchen tap. Ensuite shower has 1.5 bar pressure but very poor flow, the pipes go up to the loft and across about 5m and down to shower, probably 12 to 14m from boiler, all pipe is 15mm. I would imagine the poor flow to the ensuite is because of the length of pipe run and the fact it is 15mm pipe. Is there anyway to boost the flow to the ensuite shower other than changing the pipe to 22mm.