methods used to blow through a microbore manifold??

[warbulator]

so once again 2 of the upstairs rads have much reduced return flow.
this happened a few years back and a plumber (sadly now retired) used a hand pumped pressure bottle to blow down one of the rads return (after draining the rad and attatching the bottle to the threads of the valve usually attatched to the rad) and after a while it gurgled and freed off. cleaned system and drained down etc and put in inhibitor.
so;
1/ where do i get a pressure bottle with the right connector like the guy had?

2/ knowing where the manifold is under my bedroom floor (found it!) is it a costly/wise idea to just replace it? (will it be another drain down or could it be done freezing the pipes?)

 

[gas112]

Sentinel injector bottle ,cost about 60 quid then a few fittings .
Or you could try rigging up a hose on mains pressure from tap to push the carp out the way .
Even though flow is getting hot that doesnt mean blockage is in the return it could still be in the flow.

Manifolds dont actually nneed changing just cleaning will do it

 

[warbulator]

thanks gas112, it does appear to be the flow is ok as both inputs to rads are too hot to touch but other side is just warm.
i assumed by the fact that after draining both rads refilled quickly but are really slow to heat up