harry wrote in
:

On Wednesday, 8 March 2017 15:37:17 UTC, DerbyBorn wrote:
I have a couple of sluggish radiators and I believe (from experience
with another that got re-piped due to a kitchen extension) that there
is a partial blockage where the pipe connects to the manifold. I am
reluctant to work on the manifold as access from above is limited -
and the ceiling below is new.

I would like to try and poke something up the pipe from the radiator
valve end.

I had thought of net curtain wire and I also remember electricians
used to have a spring steel narrow tape used for pulling wires
through conduit - What was that called?
What do you think might work?

I have tried flushing it by opening the drain on the sluggish
radiator whilst slightly raising the pressure in the system. I have
used cleaning chemicals.

SWMBO now wants a heated towel rail so I need to improve the flow.

Picture of manifold when last seen:

https://goo.gl/photos/NzGn9i7YHnsPfHSq7

What you need is to flush with a hosepipe and mains pressure water.
(Garden hose?)

Be sure you don't over pressure any radiators or boilers etc.

Tried it several times to no avail.