Help!! Can't get rid of gurgling noise

[gmetten]

I have a GE model GXRM10G RO filtration system. I was having flow problems and realized my holding tank was bad and so I purchased another one. Still having flow problems and realized that my prefilter was plugged and replaced it and the post filter. (I changed the RO membrane about 4 months ago)

After this, got good flow and 87% recovery of tap water as measured by TS meter. However, daily, it continues to drain and "gurgle". I've checked the flow control valve and it's clear and have checked the line and it's clear.
If I turn off the water flow to the RO unit and wait a few hours and then turn it back on the gurgling stops for about 7-8 hours and then starts up again. Only my wife and I use the unit and are gone during the day so we don't consume much water. I'm going nuts trying to figure out how to stop this. I've done all
the testing to make sure the drain tube is only running downhill.

Any suggestions would be appreciated. I've read where I could covert my air gap faucet into a non air gap faucet--is this something I should consider.

Thanks,

Greg

[Gary Slusser]

The gurgling sound means the RO is making water. If you haven't used any for hours and it has stopped with the noise, then it starts again without you using any RO water, you have a leak allowing the pressure to fall so the ACO valve allows it to start making water again.

If not, and you've used water to cause it to make more, stand farther away from the kitchen sink or turn the music or TV volume up louder.

Seriously, put the sink stopper in the sink drain, usually the gurgle comes from the drain, not the air gap faucet.

[gmetten]

Thanks so much for your reply.

First of all, I've checked for leaks and can't find any. It's really weird because once it starts with the gurgling sounds it continues non-stop until I turn off the water feed valve. Then if I wait a little while and turn the water supply back on the gurgling stops for several hours. By the way what is the ACO valve?

It seems like once the RO has made sufficient water the noise should discontinue but it doesn't it just keeps going--that's the frustrating part. One of the threads talks about converting your air gap faucet into a non-air gap faucet and installing a check valve so bad water can't back up into the system. What's your opinion of doing this.

One last thing, when the RO system keeps running, I hear the greatest noise where the flow control valve is--it's just a small piece of plastic that fits into the tubing. I've blown it out and it seems to be fine but am I missing something here?

Thanks again for any help you can give. One good thing about this problem is that I've learned alot about my RO system!

Greg

[Gary Slusser]

When the tank is full, the auto cut off or shut off valve closes and stops the water flow. Depending on your RO and how much water you have used, it can run for hours. There is not telling how long it will run. The gurgling is not a problem, it's normal. The type and condition of the membrane, your water pressure and temp, TDS content etc. controls that. And if you use any RO water while it is making more it will take longer to shut off. If you have lost the drain line flow control or it has broken more gpm will flow making the noise louder.

You should not change the air gap faucet or add any type of check valve. A check valved isn't going to stop contamination.

Getting used to the sound or shutting off the RO is about the only choices. This assumes there isn't something wrong with the ASO or membrane etc..

There should be a small dribble type water flow out the 1/4" drain line, more than that says there is a problem.

That's all the help I can offer.

[Andy CWS]

Not all ROs have a shut-off. Or it may be the shut off valve is not operating properly.

Can you disconnect the drain line and run it into a bucket of large jug?

Andy Christensen, CWS-II

[Gary Slusser]

He has a GE. I seriously doubt that it doesn't have an ASO valve but, I haven't seen an RO without a shut off valve in like 20 years. What brands don't have one and have you ever seen one?

[Foreman]

@ Gary Slusser

Here you say "You should not change the air gap faucet or add any type of check valve."

I have an air gap faucet also. I haven’t added a check valve or anything. I'm just wondering if I can just bypass the faucet by running the brine straight to the drain. Is the air gap just for making noise so that I know when the system is running, or does it have another use that I've missed? Basically my system is set up in the basement and then run up through the cabinet to the faucet.

[Andy CWS]

Air gaps are required by many local codes.

It's purpose to prevent any gases, water, or micro-organisms from back tracking up the drain line. Your drain line often goes into an unclean destination and it may be possible for the unit to become contaminated. An air gap is supposed to create a 'barrier' to prevent that.

Some faucets have built in air gaps, other drains may just be place above the actaul drain and not make contact with drain plumbig or fixtures.
http://www.abetterairgap.com/
http://www.airgap.com/gapAro.htm

Andy Christesnen, CWS-II