On Thu, 09 Nov 2017 17:08:49 GMT, DerbyBorn wrote:

Do they all need to be thoroughly removed after a short period?

My system had 3 sluggish radiators. I had one re-piped during some
alterations. It turned out I had some sediment in the outlet union from the
manifold. Perhaps flux type debris from the original build.

Unfortunately I was out when the plumber did the job so wasn't in a
position to get the other unions checked. I now stil lhave 2 rads that are
a bit sluggish.

I would like to run with a long term cleaner in the system. I always have
an inhibitor and the water is very clean - I also have a magnetic think.

Any suggestions - is there something that I can use all through the winter
without it attacking my boiler - but might clean any partial blockages
(microbore of course)

There's this:
https://www.toolstation.com/shop/Hea...bito r/p45091
more information:
http://www.calmagltd.com/index.php/o...range/calchem/

I've been using it for a few years now.

--
Peter.
The gods will stay away
whilst religions hold sway