On Fri, 09 Oct 2009 15:57:11 +0100, Mark
had this to say:

On Fri, 09 Oct 2009 09:09:01 +0100, Pete Verdon
wrote:

Other than that, I just need a decent inhibitor, or whatever one
normally adds (not had to before). Any particular one recommended?
Finally, how do you actually get the stuff into the system? I've only
ever known my Dad's approach, of tipping it into the expansion tank of a
conventional system, but mine is sealed. I have a normal filling loop
under the boiler, and (luckily - I hear some people don't) an outside
drain cock. Is there perhaps some cunning fitting that you put inline
with the filling loop, to push a bottleful of gunk in ahead of the water?

I use Fernox. You can buy it in a cartridge for sealed systems that
you can squeeze in via the (removed) bleed screw. Despite my fears
this was easy to do.

WD-40's probably recommended for the job...

--
Frank Erskine