I have a recurring problem with the radiators on the upper floor of my
house. From experience I have de-sludged and inhibited them in late
autumn but still the upper system chokes around this time of year and
the radiators go cold. On the ground floor all pipework is 22 mm and 15
mm copper (no problems there). However, on the 1st floor it is 22 mm
copper to and from a manifold and then 10 mm microbore.
My problem is this. Am I right in thinking that the flow and return
lines should serve two seperate manifolds? My system has them both
flowing through one manifold with the 10 mm microbore flowing and
returning from it. Is this right? I would have thought that the water
would follow the easiest route i.e. by-passing the radiators and
flowing straight back to the boiler. I think that as soon as I get any
sort of sludge in the microbore then that is exactly what is happening.
Every radiator in the house has a thermostatic valve, not a lockshield
in sight. No sign of a PRV anywhere else in the system either. I take
it from that, that the single manifold in question is not some sort of
internally divided job and it is 'straight through'. Coming to the
point now....Should I split the line here and install two seperate
manifolds and some sort of pressure relief between flow and return?