RO/DI problem..

danskim · 03/12/2008, 05:49 PM

Until about a week ago, I've been able to produce RO/DI fine... for about 3 years. My house pressure is about 40psi, and I recently got a booster pump that I've been using for a month or two.

However, I got a new RO/DI unit.
From there (not the new unit's fault), I hooked up the new unit and the pressure gauge reads a very low 10 or so psi without the booster pump. With the booster, it's about 25-30psi. Basically it's not enough pressure to go through the RO membrane. At most it's a drop every few seconds.

I tried to make sure all faucets in the house and hoses outside were off, but nothing seemed out of the ordinary. Pressure in the shower seems about the same too...

Is there anything that could have caused my house pressure to fall that low? Can I do anything to fix it?

I'm going to need some RO/DI water pretty soon. Luckily I made a lot extra a few weeks ago..

I know AZDezertRat is a guru

AZDesertRat · 03/12/2008, 06:04 PM

Something sure isn't right? the booster pump, if it is a Aquatec 8800 should get your pressure up to 90 psi no matter what the incoming pressure is.
How do you have it connected? Is it with a self piercing valve? If so check to wee it is all the way open for starters. If so then try shutting it off, disconnect the line from the RO inlet and turn the valve back on to see if you have sufficient flow and pressure. If not you may need to reconnect to the cold water supply somehow, possibly another self piercing valve or a tee and ball valve in the line somewhere.
If pressure and flow appear to be sufficient, does the new unit have a flush valve and is it in the open position? What is your waste flow compared to your good flow? It should be around 4:1 waste to good.

Just for giggles, remove the prefilter and carbon one at a time and see if the pressure improves, don't leave either out for long.

danskim · 03/12/2008, 06:09 PM

It's not an Aquatec 8800. I can't think of the brand at the moment, but yes, I could get it past 90psi before I switched out the units. Now it maxes at 30psi even with the control knob all the way open.

It is using a self piercing valve, and I made sure it was opened all the way. I'll try shutting it off like you suggested. Even with the valve opened, the pressure from the faucet isn't abnormally low. I can't really tell the difference actually.

It's probably 20+:1 waste to good... The good is basically a slow drip and the waste I can hear rushing into the drain.

I also tried singling out the components, but the pressure is low even when none of the prefilters are connected.

danskim · 03/12/2008, 06:10 PM

http://www.purelyh2o.com/product.php...cat=258&page=1
That's the product I am using.

AZDesertRat · 03/12/2008, 06:17 PM

Sounds like you have an incorrect flow restrictor or none at all. Temporarily install a 1/4" ball valve on the waste line end and adjust it to approx. 4:1. I'll bet that solves your problem.
Are you sure it does not have a flush valve and it is in the open position?

danskim · 03/12/2008, 06:31 PM

Indeed! That was the problem. I had no flow restrictor attached.
For some reason, the professional model I ordered from purelyh2o didn't include one with the package... so that's confusing and annoying.

I cannibalized a piece from the older unit.

danskim · 03/12/2008, 06:34 PM

Thanks AJ!

AZDesertRat · 03/12/2008, 06:52 PM

No problem, glad I could help. I would contact Purely and have them send a flow restrictor, I cannot imagine selling a system without one? If they have them, get a capillary tube type restrictor, they are cheaper and can be trimmed to fit so you can get an exact 4:1 waste ratio unlike fixed orfice type which are ballpark close.

danskim · 03/12/2008, 07:00 PM

I just emailed them. I'll try calling tomorrow.
I noticed another thing they forgot in my order... it was supposed to come with an "all-plastic float valve." And it didn't.

03/12/2008, 05:49 PM	#1
danskim Registered Member Join Date: Jan 2005 Location: Ellicott City, MD Posts: 1,639	RO/DI problem.. Until about a week ago, I've been able to produce RO/DI fine... for about 3 years. My house pressure is about 40psi, and I recently got a booster pump that I've been using for a month or two. However, I got a new RO/DI unit. From there (not the new unit's fault), I hooked up the new unit and the pressure gauge reads a very low 10 or so psi without the booster pump. With the booster, it's about 25-30psi. Basically it's not enough pressure to go through the RO membrane. At most it's a drop every few seconds. I tried to make sure all faucets in the house and hoses outside were off, but nothing seemed out of the ordinary. Pressure in the shower seems about the same too... Is there anything that could have caused my house pressure to fall that low? Can I do anything to fix it? I'm going to need some RO/DI water pretty soon. Luckily I made a lot extra a few weeks ago.. I know AZDezertRat is a guru

03/12/2008, 06:09 PM	#3
danskim Registered Member Join Date: Jan 2005 Location: Ellicott City, MD Posts: 1,639	It's not an Aquatec 8800. I can't think of the brand at the moment, but yes, I could get it past 90psi before I switched out the units. Now it maxes at 30psi even with the control knob all the way open. It is using a self piercing valve, and I made sure it was opened all the way. I'll try shutting it off like you suggested. Even with the valve opened, the pressure from the faucet isn't abnormally low. I can't really tell the difference actually. It's probably 20+:1 waste to good... The good is basically a slow drip and the waste I can hear rushing into the drain. I also tried singling out the components, but the pressure is low even when none of the prefilters are connected. __________________ Dan The sea, once it casts its spell, holds one in its net of wonder forever. -Jacques Cousteau

03/12/2008, 06:10 PM	#4
danskim Registered Member Join Date: Jan 2005 Location: Ellicott City, MD Posts: 1,639	http://www.purelyh2o.com/product.php...cat=258&page=1 That's the product I am using. __________________ Dan The sea, once it casts its spell, holds one in its net of wonder forever. -Jacques Cousteau

03/12/2008, 06:31 PM	#6
danskim Registered Member Join Date: Jan 2005 Location: Ellicott City, MD Posts: 1,639	Indeed! That was the problem. I had no flow restrictor attached. For some reason, the professional model I ordered from purelyh2o didn't include one with the package... so that's confusing and annoying. I cannibalized a piece from the older unit. __________________ Dan The sea, once it casts its spell, holds one in its net of wonder forever. -Jacques Cousteau

03/12/2008, 06:34 PM	#7
danskim Registered Member Join Date: Jan 2005 Location: Ellicott City, MD Posts: 1,639	Thanks AJ! __________________ Dan The sea, once it casts its spell, holds one in its net of wonder forever. -Jacques Cousteau

03/12/2008, 06:04 PM	#2
AZDesertRat Moved On Join Date: Jan 2002 Location: NW Phoenix Posts: 16,621	Something sure isn't right? the booster pump, if it is a Aquatec 8800 should get your pressure up to 90 psi no matter what the incoming pressure is. How do you have it connected? Is it with a self piercing valve? If so check to wee it is all the way open for starters. If so then try shutting it off, disconnect the line from the RO inlet and turn the valve back on to see if you have sufficient flow and pressure. If not you may need to reconnect to the cold water supply somehow, possibly another self piercing valve or a tee and ball valve in the line somewhere. If pressure and flow appear to be sufficient, does the new unit have a flush valve and is it in the open position? What is your waste flow compared to your good flow? It should be around 4:1 waste to good. Just for giggles, remove the prefilter and carbon one at a time and see if the pressure improves, don't leave either out for long.

03/12/2008, 06:17 PM	#5
AZDesertRat Moved On Join Date: Jan 2002 Location: NW Phoenix Posts: 16,621	Sounds like you have an incorrect flow restrictor or none at all. Temporarily install a 1/4" ball valve on the waste line end and adjust it to approx. 4:1. I'll bet that solves your problem. Are you sure it does not have a flush valve and it is in the open position?

03/12/2008, 06:52 PM	#8
AZDesertRat Moved On Join Date: Jan 2002 Location: NW Phoenix Posts: 16,621	No problem, glad I could help. I would contact Purely and have them send a flow restrictor, I cannot imagine selling a system without one? If they have them, get a capillary tube type restrictor, they are cheaper and can be trimmed to fit so you can get an exact 4:1 waste ratio unlike fixed orfice type which are ballpark close.

03/12/2008, 07:00 PM	#9
danskim Registered Member Join Date: Jan 2005 Location: Ellicott City, MD Posts: 1,639	I just emailed them. I'll try calling tomorrow. I noticed another thing they forgot in my order... it was supposed to come with an "all-plastic float valve." And it didn't. __________________ Dan The sea, once it casts its spell, holds one in its net of wonder forever. -Jacques Cousteau