Draxen wrote:
Many thanks to those who responded to the previous thread, still got
problems though...

I refilled the Saunier Duvall boiler, closed off the filling and
failsafe valves, and bled the radiators again. The central heating
pressure gauge on the boiler is now hovering just a shade above the 1
mark.

I think there's some sort of pressure problem though, the water
doesn't seem to be getting moved around the system.
The radiator nearest the boiler gets up a lukewarm temperature, I can
feel a slight warmth from two others, and the radiators furthest away
from the boiler are stone cold. Unfortunately these two are the
living room and bedroom
When I bled the radiators a trickle of water oozed out, every other
time I've done it there's always been a bit more pressure and the
water would jet out with about the same force as a squirt from a
water pistol.
The boiler itself is acting wierd. It's too quiet, there used to be a
rhythmic sound to it, hard to describe, but you could tell it was
working, now it's silent most of the time. The burners don't ignite
for long either, 5 to 10 seconds every 15 minutes or so.
I've tried all the settings I can think of, from the summertime
hot-water only all the way to get-me-through-the-nuclear-winter full
monty. Nothing On max settings the temperature gauge rises to
around 50 degrees C, when it was working it used to get up to 70
degrees.

Is there anything more I can try ?

There could air in the boiler. There may be some way of bleeding the boiler
itself.
Some combis have an automatic bleed valve. See installation/user manual.
Another possibility is the pump has locked due to running dry.
There is a standard procedure to try to free it.
Worst case is that something has been damaged by trying to run the system
without sufficient water