S
sweep
Sorry if this has been asked before or in wrong place first post.iv just moved to a bungalow and had a valiant ecotec plus fitted 837 r1 fitted (cheap) now the wife has decided she wants new rads fitted old ones scruffy and imperial .the pipe fro boiler is 22mm with eight mill going to rads eight in total im eventually going to convert attic so will need min 3 rads up there as well .am i better to change all the heating pipes to 22mm then branching off this to 15mm to rads if im changing radiators anyway or the 8mm be good enough. p.s thanks in advance stevie