Reverse Osmosis Drain constantly running

[dgrabke]

Hi there

Can't get my RO to stop draining. If I shut off the tank, it shuts off as it should. I replaced the check valve and the ASOV anyway to no avail. Has a permeate pump. I don't know what the incoming pressure is, but it was fine for years.

Any ideas as to what to check for?

 

[CountryBumkin]

Make and model?

 

[Sponsor]

 

[dgrabke]

No make or model. Was purchased from ebay from H2O splash. Standard housings with aquatic permeate pump. Using Dow filmtec membrane 75 gpd

 

[Reach4]

Based on what I read, the problem could be the Automatic Shut-Off Valve. That should shut off the flow when the tank pressure reaches some percent of the incoming water pressure. I guess that something that prevented the pressure from getting high enough in the tank could keep the water flowing, even if that valve was good.

If you checked the precharge air pressure while the tank was full, that should closely reflect the water pressure in the tank. If that pressure was near incoming water pressure, I would think that would indicate a bad Automatic Shut-Off Valve.

 

[dgrabke]

Thanks for the reply. Any theory as to why it would shutoff as normal when I cut the tank off (mimicking a full tank)?

 

[Reach4]

Thanks for the reply. Any theory as to why it would shutoff as normal when I cut the tank off (mimicking a full tank)?

Just a theory. Maybe it would shut off eventually, and it just builds pressure very very slowly when charging the tank. Suppose you can produce 0.001 gallons per minute. That would take 8 hours to produce 1/2 gallon of water and shut off. Yet that production might be able to pressurize the water-filled tubing pretty quickly.

How new is your membrane?

 

[dgrabke]

Brand new. Two days old.

 

[Reach4]

After it runs a few hours, I would check the air pressure and the incoming water pressure.

 

[Shelbycobra427]

I'd suspect the permeate pump. I have one on my RO system and on the system I installed at a friend's house. Together we've gone through 3 of them and I only installed the systems about 6 years ago. I've seen them fail in a couple of different ways and wouldn't be surprised if that was your issue. If you have some extra tubing and a little time, you could bypass the permeate pump and see if your problem goes away.

 

[Rmk9785e]

Just a theory. Maybe it would shut off eventually, and it just builds pressure very very slowly when charging the tank. Suppose you can produce 0.001 gallons per minute. That would take 8 hours to produce 1/2 gallon of water and shut off. Yet that production might be able to pressurize the water-filled tubing pretty quickly.

How new is your membrane?

I am having exactly the same problem since yesterday on a one year old kitchen sink RO system with 6 filters that has no make or model on it. Water keeps draining continuously but stops about 1/2 minute after closing the tank valve. It had been working fine but in the last couple of days, there were some low pressure issues caused by some other plumbing work. Could that have caused this problem? What steps should I take before calling the installer?