Hi,

My new flat has a Worcester 350 combi. One of the radiators needed
bleeding, so I did the honours today and after an enormous amount of
air bled through it started working fine.

Soon after, the combi stopped working, and the "low pressure" light
came on. I'm hoping there's nothing seriously wrong and the system just
needs topping up with water. However I can't figure out how to use the
filling loop.

Googling old threads, the filling loop looks just like this:
http://www.pegler.co.uk/img/prod/DB_images/30055_a.jpg - a metal pipe
with a screw at one end and an allen-key thingy at the other. But what
do I do with it? I tried turning the screw and I could hear water
gushing but it didn't seem to move the water pressure meter. Should I
turn the bolt on the other end as well?

Also, I now seem to have a slow dripping from the "allen-key" end of
the loop. Is this bad?

In case it's not obvious, I don't have much of a clue about these
things, but would really like hot water without having to call a
plumber next week!

Zara