1 rad hot at top cool at bottom

[cyril]

have rad in hall worked fine until recently, now only hot at top and cold at bottom flow is at top right and lockshield is at bottom left. all rads upstairs work fine mad hot ,kitchen is mad hot this is a new rad have 2 rads in lounge 1 is ok could be better and 2nd is hot at top and warm at bottom, have tried to balence system but only makes kitchen worse and lounge 2nd rad worse still mad hot upstairs with lock sheilds only a fraction open. could this be sludge in hall rad? also have rad missing in bathroom could this have anything to do with problem both pipes are capped in bathroom.system is on 22mm mainn run up and feeds down stairs in 22 mm then changes of to 8-10mm micro bore. bit long winded sorry ,can any help i,m stuck with this !

 

[chrishutt]

could this be sludge in hall rad?

Almost certainly. As a minimum you could isolate rad (close both valves), undo unions and drain (lots of thick black sludge - protect carpets, etc.), take rad outside to flush water through (hose pipe) if you want to be more thorough.

However rest of system will also have a lot of sludge, so flushing of whole system would be better. Various methods, using mains pressure water or power flushing with pump. Search for this topic - it's been done.

 

[cyril]

I'll give it try over weekend thanks ....