On 11 Mar 2004 01:16:59 -0800, in uk.d-i-y
(Robert) strung together this:

It is a pressurised system - I did remember to refill it - When I
measure the pressure at the expansion vessel the pressure is 0.5 bar -
it used to be just over 1 bar.

The pipes are mainly microbor (3/8")

There is definetly no air locks in the system. Since all of the
radiators heat proberly I don't think there is a problem with the
boiler or programmer.

Not neccesarily.

We have a 2 storey house

And?

What is a filling loop??

If you re-pressurised the system you should already know this one.
It's a connection, usually a braided silvery flexible pipe, between
the cold water supply and the heating return.
I still don't know what type of heating you've got.
--

SJW
A.C.S. Ltd.