So I was reading this post and I don’t see where they are supposed to go.. can someone explain how to put them in and where? I don’t know which Z50 I have but I’ve had it about 4 years and now it is leaking. I suspect I need to change the o rings but can’t find where the large ones (2 spares) go."Marantz separates" - had forgotten about them! Ha ha, now I know exactly the colour you mean...
+1 to above; keep the spare O-rings, at some future date when cleaning the tank, the current set will disappear down the plughole.