Auto shut off valve

[sharuq1]

Sorry, I meant the thingie marked "ASOV" on the Melev site above (auto shut off valve). Mine is attached to the end of where the three canisters go into the membrane and then goes to the DI. No water was going through it, so no new water was being made, which means my whole unit was sitting there stagnating for a day.
I took mine apart and the rubber inside looks degraded. I rinsed it all under hot water and put it back together and water is flowing again through the "thing". I need to buy a new one because I don't think that'll work for long.

Do we even need this thing or what? I'm not too sure what use it is....