central heating fitting

[tony_m]

Hi
I am going to install a small central heating system (combi powered) over 1 & 1/2 floors. The distance to the first rad and last rad are roughly the same, which is about 5 meters. I was thinking of running 22 to the first (Flow) and last radiator Return and connecting each remaining rad ( 3 of them ) with 15mm. Would this be correct or should iI use 22mm all round and tee off with 15mm to each rad? the distance between first and last radiator is 12meters, directly.

 

[Bahco]

Quicker warm up times and less resistance if you branch off the 22 mm in 15 mm feeds to each rad.
You could feed 2 or 3 rads in 15mm but for the minimal extra cost I would run with the 22 mm .

 

[tony_m]

A Wickes leaflet described pipe sizeing as " the flow and return pipes will always be the same size to and from any particular part of the system. with this information it is a straightforward matter to work out the 15 and 22mm requirements."????.
I have seen it done in 15mm between rads, but seeing as its my own place I will do what you said and use the 22mm.
Thanks for your reply.

 

[Bahco]

Worth lagging the 22 mm under your floorboards too with that foam tubing.
Well worth the £10 or so cost