On Sun, 15 Oct 2006 17:22:05 +0100, Andy Hall
wrote:

There's really no reason why a properly maintained heating system
should be suffering from sludge.

If it is a sealed system (no header tank on loft) then the only action
that should be needed with a clean system is to dose it annually with
corrosion inhibitor - cost about £20.

I have to confess, that is something I haven't done for about 3 years,
....until the other day, when I ran it with de-sludging solution and
then flushed and filled with water+inhibitor.

Jim D