@Best Thanks for your reply. We’ve got plastic pipes, to the Radiators, in the 2 Extensions that were added to the house, by the previous occupier. The rest are copper..
But I just got a call from my RG Installer. (We’ve had to put the installation back a day, to Tuesday) He says we don’t need to have the Spirovent RV2 de-aerator fitted..!
The ATAG Economiser has a built in ‘air-vent’ and as it’s going upstairs, at the
highest point in the system, I don’t need an Aearator.
So that’s a hundred odd quid he’s saved me!
I knew I liked him!