Greetings and Felicitations, O Great Ones!
It is I, Robot, er, Francis. (And the Thunderbirds ("THE Thunderbirds?!?!?!) movie is pants!).
I have run the system for about a week with cleanser. Flow now up to 82 deg C, return about 70 deg C. I have to balance system now (Is that Phil's faq?).
Pressure on input to gas valve 20mbar.
Came across a
Schnellkupplungen for a Membrandruckausdehnungsgefäß
while Googling.
My search for Schnellkupplungen for a Membrandruckausdehnungsgefäß has shown me that what is involved is an item that enables the expansion vessel to be isolated for servicing without draining the whole system. Some contain a locking cap that is sealed in a similar manner to electricity and gas meters.
It seems that these conform to regulations in some parts of Europe.
One of my 2-port zone valves seems to be faulty. When DHW valve is open the upstairs rads seem to heat up. I don't think it is reverse circulation. The upstairs zone valve motor seems to be working and is not calling for heat, but flow pipe gets warm
FrancisJK