Aah! this is mistake! Clearly I was tired/in a hurry when I looked at this plumbing!
So, your second membrane add-on kit is installed in reverse from the first one, hence the unusual plumbing here…
— First of all, I see zero flow restrictor on the waste line of the second membrane, so it’s basically non-functional! — you’d want both membrane waste lines teed together into one waste line/one flow restrictor, or a correctly sized flow restrictor for each of the two waste lines… (for now, I recommend teeing both waste lines together prior to your existing flow restrictor!)
— The pressure gauge is currently on the product water side of the RO membrane (blue line) this will never exceed 40PSI (automatic shutoff switch turns off water supply at 40PSI RO product water line pressure)… this is why it’s reading zero!
— the pressure gauge, and associated tee should go on the RED line, before it goes into the first RO membrane!
I’m shocked at myself for missing that!
)
