REPLACING SMALL BORE PIPES

[remus]

Hello, heating system had 10mm pipework. I have changed the upstairs to half inch and want to do the downstairs. However, the pipework from near the HW tank to the Tee junctions where the flows split, is half inch. Will this cause a problem or should I change it to inch please? I would rather not if it isn't much of a problem as I'm bound to tear the expensive floor covering!

 

[gas4you]

Depends on the rad outputs. if they all add up to less than 4Kw (14000btu approx) then 15mm will suffice. If not then a certain amount of 22mm will be needed to let the rads heat up quickly

 

[remus]

Dave, thanks. It's a 3 bed semi, not sure of BTU. My concern was that there would be 15mm feeding the tee which sends 15mm downstairs and 15mm to the upstairs rooms. It's bound to heat up quicker than the old 10mm, or 8mm it might have been, before I did the upstairs conversion a couple of years ago the rads took ages to warm up and only to tepid in some cases.

 

[gas4you]

It should really be 22mm that is feeding the 'T' that splits up/down rads. Even though 15mm will get them hot it will take much longer than a 22mm flow and return.

 

[remus]

Thanks Dave, thought I might have to. Will have te be very careful with the floor covering.