Central heating pipe routes

[GlosRob]

I need to extend my central heating from my newly built extension in to the old part of my house. I need to feed 3 rads in separate bedrooms on the first floor and then to feed a towel rail in a bathroom a rad in the utility and a rad in my lounge on the ground floor.

Can I run my 22mm flow & return down the middle of the hall and tee off in to each room ? If I tee off do I reduce to 15mm straight from f&t or keep it 22 until it meets the rads.

Does this makes sense ? I have a pic but can’t work out how to post pictures.

 

[SimonG]

Run your mains in 22 and reduce to 15 to rads.

 

[GlosRob]

Run your mains in 22 and reduce to 15 to rads.

So when I tee off from the flow and return continue with 22 mm and only reduce at the rad point or run 15mm from the tee off point.