Can central heating manifold take 15mm pipe

[Sinny]

I'm changing downstairs manifolds in central heating to a new ones, old manifolds can only take four radiators and i wan't to fit a fifth, also old one's constantly leak. My question is, while i'm doing this job can i replace all 8mm pipe with 15mm, do manifolds take 15mm pipe or are they made for microbore only. Chris

[chris_on_tour2002]

yes they do come in 15mm, in fact they come in all manner of sizes, many a good deal larger than 15mm. a more important question is whether it will suit the rest of your system.