Converting 8mm microbore to 10mm

That is totally and utterly perfect in every way.

They learn some grammar.

" THEY learn some grammar" ?

Can I have some of what you are on please ?

That's what I said diddle I.

Looking at the other posts it would appear that you have been introduced to a range of replies.

Provided:

then keeping the existing 8mm and 10mm pipes will be a good choice.

Obviously 8mm pipework is even more prone blockage than larger sizes but isn't automatically a problem.

The existing system worked on the basis that the difference between the flow and return temperatures would be somewhat more than a system using larger pipes. This is all to the good when using a condensing boiler.

Thx Ed ...I'll get the new boiler fitted and see how it goes ..

Stuart .

It didn't. It worked on a temp differential of 10C or 11C like any other system at the time, no matter how big the pipes.

Which there shouldn't be on a primatic system and this means the pipes often do clog up more than other systems.

Inasmuch any domestic system is 'designed' rather than estimated (usually quite well) then microbore systems have a larger difference between flow and return temperatures than systems using 22& 15mm.

Only if it was not sized right.

I'm a bit confused by references to different sized pipes here . Do you mean the two pipes to and from each rad are different sizes( I'm presuming you don't mean that) or,as in my case different rads have different sized pipes( 8mm or 10mm) connecting them to the 22 mm F+R ( either from tees or from a manifold) ?