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Home Improvement--General/RO System is conatantly gurgling in the drain


A.N. wrote at 2008-02-24 21:40:07
I also have the same problem with a Sears RO unit.  It doesn't make too much noise but when looking into the hole of the faucet air gap, water is running constantly into the drain.   I don't remember it being this way before.     reading your advise, some valve must not be functioning properly, I just don' t know which valve to replace.   I am going to replace the diaphragms of the shut off assembly when I receive them.  I will report later to see if that is the cause.

Peter M wrote at 2008-12-12 00:18:10
Follow up on this thread.  I am experiencing EXACTLY the same scenario.  My system has worked fine for 3+ years and now it constantly makes noise into the drain.  It is seeming to be a recurring problem.

fishntyme wrote at 2009-12-05 02:12:29
I have the same problem with a PurWater system. Was working fine now continuously runs. I tried changing the membrane, membrane housing, auto shut off twice, tank, pre-filters and flow restrictor. Pretty much made a brand new system and still the same result. Will run for a while shut off for a minute and then start running again. I can hear it leaking (down drain) from somewhere but cannot find it.

Anyone know why? My incoming water pressure is 85psi.

RayBob76 wrote at 2014-02-19 00:11:32
You have a defective auto shut-off valve.  This "ASO" detects equalization between your house water pressure and your storage tank pressure and shuts off the flow of water through the membrane and down the drain to prevent the system from running all the time (as you're experiencing.)

Check with the manufacturer (  They may be able to refer you to a dealer who keeps the part in stock. It's a simple and inexpensive repair, but it will require a new "ASO."

Steve wrote at 2014-05-03 23:27:30
Thank you RayBob76.  Great answer and I will definitely remember that for the future.  It's people like you that really make this site good!!

Steve Young

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Home Improvement--General

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Steve Young


I will answer questions dealing with home improvement. My specific areas of expertise are flooring (except carpeting), all types of carpentry, water treatment, and minor electrical. I have also built several treehouses and am currently considering expanding my business to concentrate on children's play areas. I love working with all kinds of wood. My favorite types of home repair/remodeling are water treatment, hardwood flooring, cabinetry, bathroom remodeling, and kitchen remodeling. I also have knowledge in residential water treatment, including filters, softeners, reverse osmosis systems and various other types of treatment systems.


I have been working in various forms of construction both personally and professionally for the past 20 years. I am currently the Owner/Contractor of a home repair/remodeling company.

I have a BS in Environmental Engineering and have done Masters work in Management Development. I have also attended various community college and fine arts classes in the Piedmont Triad area and EPA water quality certification classes.

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