Many systems these days use microbore piping rather than the usual copper 15mm pipework. Arguments for an against. The resistance to flow in thinner pipes means a pump has to work a bit harder. Thinner pipes mean the pipes themselves have less of a heating effect. At the same time, this gives your heating system a much lower overall volume of water to heat and then circulate.
Don't shoot me, I'm only the piano player. I DON'T work for or on behalf of EON.Next, but am willing to try and help if I can. Not on mains gas, mobile network or mains drainage. House heated almost entirely by baby dragons.