The message .com
from "Charles Middleton" contains these words:

Is this just an air lock that hasnt worked its way out yet?
What a weekend

Mike Ring wrote:

I open one loop at a time, pretty much in the above order, and blast and
bleed them one at a time.

Compo wrote:

\snip\
This morning I tried forcing water up through the donstirs manifold.
This moved a lot of air but has not fixed the problem.

Apart from the obvious spelling mistakes the above turned out to be the
solution to my problem after all. In desperation I reconnected the hose
to the downstairs manifolds and, with all downstairs rads open and
upstairs (which were operating after a fashion) closed, forced water up
through the system (both sides in turn) until it escaped through the
header tank overflow. This appears to have moved my airlock around and
immediately masses of air appeared in two of the radiators. After
repeated bleeding the system appears to be getting back to normal. I am
currently opening each of the upstairs rads in turn and bleeding the air
from them.

--
Cheers,

Compo.