On 02/12/2017 09:47, Tim Lamb wrote:
In message , Vortex12
writes
In New Year will be replacing an ancient heating system in a flat.
Total 8 radiators with all the piping logically coming back to a
single central point.

I am thinking an 8 way UFH manifold (John Guest) would make a very
elegant solution at this location.

Of course flow temperatures may be 60+ degrees, whilst normal UFH
temperatures are much lower.

Can anyone reason not to use this approach?

You can buy manifolds for CH anyway.
My heating is done in plastic now as its easy to run and there are no
joints in the pipes.

You need barrier pipe not plain pipe, but most of it is barrier pipe
these days. It wasn't 30 years ago when I first used plastic on the CH
system.


You will need to wire in thermostats and use the control valves to give
individual room temperature control.

Mine uses 22mm pipe and tees to make the connection to the 7 zone valves
rather than a manifold on the feed but uses a microbore manifold for the
returns. There are reduces on the valves to drop to 10mm for the plastic
pipe.


One issue is the bathroom where using conventional stats may breach the
zone rules.

Put it on the same feed as the bedroom/landing using a bigger rad than
needed and fit a radiator valve to stop it getting too hot.


I'm still at the laying the pipework stage so haven't got to grips with
the temperature control range of the valve used to supply the manifold.

Towel rails?

Boiler overrun bypass?


Most system and combi boilers include everything in the case these days.
You only need the flow and return (plus cold in and out for a combi) and
a pressure release pipe on most of them. Nice and easy to fit.