evoracer

are you running a electric/premate booster pump, whats your source water inlet pressure?

oh, and where did you get the 3 different ASOV valves?

First one came with the unit, the other two came from the hardware store. Not sure if incoming pressure. Is there a minimum pressure needed? Next step u guess would be to measure incoming pressure (need a pressure gauge) and then get a good ASOV from Melevs Reef?

i am sure there is a min pressure (what that pressure is, i dont know. but knowing your pressure will tell you when your filters are getting used partially clogged as well as let you know if you membrane will work correctly.
i asked what your pressure is, but if you know your membrane pressure (thats usually where most pressure gauges are installed so you know how things are working.) mark might be able to tell more.

Marc sells lots of RO units, and i havent heard any negative, so i would say if you got one from him, it would be of good quality. (make sure the water going in and out are correctly orientated.)
I got my unit from BRS, and have no problems, so its another option.

i asked if you have a booster pump, because if so, and you dont have a working pressure/electric switch, then it can over power the RO unit and cause the ASOV to not work.

Your system may have trapped air in it which is preventing the ASOV from functioning properly. With it turned on and producing water (without the DI section connected), lift one side up at a decent slope -- 30 degrees or so, and hold it for 20 seconds. Lower it back into normal position, then lift the opposing side and hold for 20 seconds. Any trapped air in the system should be forced out, and the ASOV should resume working properly. Turn it off and see if it shuts off.

My own decided today not to shut off. Guess it's time to replace mine as well.

Will try! If not then I'll order a new ASOV and a new check valve for grins. So Marc, is there a minimum pressure I should have or is that not related IYO?

You need 40 PSI for the membrane to operate properly, and 60-80 PSI for it to be very efficient.

If your system is leaking anywhere, for example if you use a float valve in a container instead of a ball valve cut off, it may not shut off.

I had the same trouble with mine it was in coming water volume was to low you can have pressure right and still have low flow. The hammering is air in the valve because your booster pump is pulling more volume then the incoming water is putting out ( my gauge still read good at 85psi while this was happening ) Cast iron lines in part of the house where the cause. Moved mine to otherside of the house by the in coming line and works great. I can tell you now that the asov does not work proper past 110 psi unrestricted mine is at 120 with the pump on and it is hit and miss with shutting off but back down to 110 it works flawlessly

We don't have booster pumps here, and I don't have one on my RO unit. I was looking into a permeate pump, looks like it may solve this problem (by eliminating the ASOV) and make the system more efficient overall. But first I will test water pressure at the unit and go from there.

hey just a though your probably going to want to keep some extra prefilters and di resin around at 750 tsd incoming you will go thur some. While running is your prefilter cups staying full or is the water level dropping or do you every get a milky looking water from your spigots from air being in the water

Ok finally got to the bottom of this one. The check valve on the output of the membrane was bad. It was both partially plugged, causing lower output, and didn't restrict backflow, causing the ASOV to not shut off. So now that the check valve was replaced the system works correcly, finally. My output is still low (about 48gpd out of a 150gpd membrane), but I chalk that up to the rediculously high TDS.

Glad you got it hashed out mine has been acting up again Ill have to check my check valve. Im read to go to a solenoid valve on the input

What is the PSI of your system, Jimmy? And what is your TDS?

My RO/DI system came in last week and I need to get it installed.

Marc was that question for me (Jeremy)? I have not checked the incoming pressure, I don't have a gauge. At this point in time it is serving me well as is, but i know i will eventually want more output. The incoming TDS is ~750, output from RO is 20-30.

Sorry, I'm terrible with names.