Microbore or half inch ?

[Dan]

Preferring to stick to copper , I currently have a manifolded system that feeds all the rads with microbore copper piping, I get the feeling that the pump struggles with this for circulation, and I'm thinking of replacing my boiler any way and considering replumbing to 1/2 inch or the nearest metric equivalent, what do you guys think ?

[FnDaily]

Geeza .. how many rads ? .......... over how many floors ... etc etc .. why do you think the pump struggles ?

[MadMike]

Got to be simple maths innit ? pump works harder to push fluid through small bore pipes ?

[Dan]

Geeza .. how many rads ? .......... over how many floors ... etc etc .. why do you think the pump struggles ?

Sorry guys Ive been away for a bit its 11 rads on 2 floors .. I rekon microbore restricts the flow (obviously)

[gardener12]

well it does have the advantage of less mess, so if the flow is less the pressure must be higher right ? so the pump works harder

[dilligaf]

Its not a pump, its a circulator, it helps the natural gravity circulation of hot water. Badly designed systems need more assistance.
If your getting a new boiler get the system (power) flushed to remove all the sludge (iron oxides of various sorts), as boiler manufacturers will not uphold their warranty if its not done, the system will work a lot better, and will be more economical to run.
Mini / Microbore systems work fine if they are properly designed.
Personally I would opt to change the system to 22mm and 15mm pipe sizing to allow greater Kw input to the radiators, however the upheaval of repiping the whole system would be rather messy, time consuming and expensive.