On Sun, 02 Nov 2008 12:25:44 +0000 (GMT), "Dave Plowman (News)"
wrote:

In article ,
wrote:
18 months ago I got my CH boiler replaced and I made sure the guy
connected up the existing drain pipe to the outside down pipe and also
fitted a filling point beside the boiler for the concentrate .It's
just a branch off the pipe from the boiler which is turned upwards for
a few inches and has a compression stop on the end that you remove
when it needs refilled or topped up.

You'll still need to drain down before adding concentrate - and rather
further than if you use the highest rad in the house. In other words,
drain about a bucket full out of a sealed system. Add the concentrate
via the bleed valve on the highest rad. Then refill and with luck only
that rad or it and the others on that level will need bleeding.

I take it that reply is directed at the OP?

No - to you.
Well in that case maybe it would have been helpful if you had
explained why I should do it that way instead of using the "filling
point" which seems a lot easier .
And none of the radiators are "highest" . They are all on the same
level as I live in a flat .