Post by magicmanalex on Jan 29, 2016 10:51:30 GMT -5
What is the correct pressure for both the internal and external expansion vessels on a Powermax HE 150?
The label on the front of the boiler says the 'operating pressure' for both is 2.5 bar.
Everywhere else says 1.0 bar for the internal expansion vessel (as does the manual).
The external one (balloon shaped thing in the attic) is 'pre-charged' to 2.5 bar (although that one is showing 26psi at the moment which is low).
So assuming there are no water leaks out of any of the Schraeder valves, should I pump up the internal one to 1.0 bar and the 'balloon' type one in the attic to 2.5 bar?
I'm going to be draining the system fully first as a couple of TRVs have VERY slow leaks.
Do I have to leave the drain cock (or a bunch of radiator bleed valves) open when I'm pumping up the expansion vessels, or should they all be closed?
