Fernox or Sentinel for recently powerflushed very dirty microbore system ?

[PSH]

Ermintrude has got me thinking - I did wonder whether the system could not handle the piggy backed rads, but what is puzzling is the fact that there are 6 other rads on the system,sharing 3 other feed and return legs/runs using "T" connectors which are running perfectly hot . The work colleague who helped me do the job seems to think that the reason all the other runs are working is because on the run which is not working ,the feed and return pipes come up vertical into the ceiling ,then run along the top of the plaster board ,then start to rise on their approach to the return manifold,which he thinks could be trapping air bubbles which the water flow cannot shove along to where the auto vent valve is located. Q: Do you think I should try and level off these pipes so that there is no gradual incline on the run ?

 

[Ermintrude]

Rise is ok means air will go to manifold. Take rad off and run 10l out of each valve , that will clear air. Microbore can only deliver a small amount of heat 2kw ish?

 

[PSH]

Having waited a week to see if the auto bleed valve in the attic had got rid of all the possible air in the system, both the lounge and wet room rads are still cold,with just both the feed pipes getting hot. I have let 10 Ltrs of water run from both pipes as suggested .I forgot to say in my original post,that the guy who did the power flush,also fitted a Magnaclean filter ,which did trap a fair amount of black sludge during the first 6 months but is now running clean. The only thing i can think of doing now is to fiddle with the pipes in the attic to get them running as level as possible from where they enter the attic to where they meet the manifold. Any more ideas chaps,as it is now getting cold and my Mother suffers from COPD ,and she is having to use a hot air blower to warm the room up ,which is not ideal .

 

[Ermintrude]

Pipes should rise to manifold to encourage air to. Top.

 

[PSH]

Is that for both the feed and return pipes ?