RO/DI Question

[RJS]

I purchased a Marine Depot KleanWater Advanced 4-stage RO/DI system, and for $80 added on the drinking water system (a 3-gal tank and sink-installed faucet. And my problem is that I cannot get the waste water line to stop when the system stops calling for RO or DI water.

I emailed the Marine Depot customer service folks and received a link to a video that shows how to install the auto shutoff component. I faithfully followed the video (happy to forward the link upon request) and got a mixed bag of results. At first, it started to work okay, the waste water line opened up when I was making RO or DI water, and then after a slight delay it stopped - good, as it should.

Then I attempted to run DI water again, and the third or fourth time the waste water line again would not stop. I shutoff the water supply and restarted the process, but this time waste water barely trickled out, and again never shutoff until I turned off the water supply.

No flow restrictors came with my system, unless they're built in. I received two skimpy, smallish inline check valves. I installed them (one on the line to the drinking water tank and one on the waste line, but they seem worthless and at one point I heard pressure trying to escape them.

So I have several questions about things I think could be contributors to my problem, but would rather ask the many seasoned, experienced veteran aquarists on this forum, has anyone had this same type of problem? How did you resolve it?

I'm getting solid results on the RO and DI water production. TDS is in the mid to high 200's on the water supply and DI output is zero. But, I'd love to be able to get this system to function the way it is intended without wasting a bunch of water. Thanks in advance for any help.

 

[redfishbluefish]

@AZDesertRat should be able to help.

 

[RJS]

@AZDesertRat should be able to help.

Thank you, @redfishbluefish

 

[AZDesertRat]

Does your diagram look like this one?
http://spectrapure.com/huds/4-STAGE-DWK-RODI-NAG.pdf

Note the placement of the check valves. The check valve by the ASOV is important.
When the system is running pick it up in your hands and slowly rotate it all around to release any trapped air in the housings. This will give it a more positive shutoff since air compresses and water does not. How long did you wait for it to shut off, there can be a pretty good delay sometimes.

 

[RJS]

Thank you very much @AZDesertRat. I didn't have it setup that way. But I just set it up as depicted in your diagram, and I'm still having the same issue. I'm thinking that either the ASOV or the check valve is faulty.

Customer service at Marine Depot responded in the following way, so I followed the guidance on the video. That didn't help.

Hello Robert,


Thank you for contacting Marine Depot. It sounds like you don’t have the automatic shut off valve installed properly. I circled the part in yellow below so you can see what part I am referring to. Please check out this video on how to install an automatic shut off valve on a RO system: . This is the part that will stop water from coming in once your pressure tank is filled up. I hope this helps!

 

[redfishbluefish]

This is just a guess, but if you don't have high enough pressure, could that cause the ASOV not to shut off? By chance, do you know what your water pressure is?

 

[AZDesertRat]

There are high pressure and low pressure versions of ASOV valves but normally the low pressure version works fine.
Take a look at this link and make sure you have the IN on the high pressure side from the RO membrane as shown.
http://www.buckeyehydro.com/content/Auto_Shut_Off_Valve.pdf

 

[RJS]

This is just a guess, but if you don't have high enough pressure, could that cause the ASOV not to shut off? By chance, do you know what your water pressure is?

Thank you @redfishbluefish. That is a possibility I've been pondering, and plan to pick up a separate pressure gauge on my way home from work to test it. I think the pressure feels pretty good, but don't know if it is sufficient for efficient RO/DI operation. Thanks again.

Robert

 

[RJS]

There are high pressure and low pressure versions of ASOV valves but normally the low pressure version works fine.
Take a look at this link and make sure you have the IN on the high pressure side from the RO membrane as shown.
http://www.buckeyehydro.com/content/Auto_Shut_Off_Valve.pdf

Thanks, @AZDesertRat. This diagram is great. I'll double check my setup for consistency with that instruction from Buckeye. I have the type of ASOV labeled as Type A on the diagram.

Thanks again.

Robert