Will an icemaker work with RO water?
First of all, you can make ice cubes from water produced by reverse osmosis systems. In fact, ice made from reverse osmosis (”RO”) water produces cleaner, clearer and better tasting ice cubes because most of the contaminants are removed from the water. So, just because water is purified by a certain process, (in this case, reverse osmosis), has no bearing on whether you can make ice. I prefer “clean ice” - in many cases it is perfectly clear, except for a little cloudiness in the center of the cube. Another benefit is that the cube is harder and melts slower. Most people like that as well.
So, why would an ice machine technician tell you that RO water won’t work on an ice machine? I suspect that his experience is that he has seen many situations where he is called on a service call and found that when the reverse osmosis system was disconnected and the ice-maker was connected directly to the house supply, it worked. That doesn’t mean that RO water won’t make ice cubes, however. When you supply an adequate volume of water at an adequate pressure, any ice-maker will produce excellent cubes.
The problem with an RO system on ice-makers (especially the “basement bar-type” machines) is that those types of ice machines use a large amount of water. Believe it or not, some of those machines can use 80-90 gallons of water a day! Unless you have a high volume reverse osmosis system, it is futile to try and supply RO water to that kind of ice-maker.
Another issue is pressure. Many new ice machines require 30-40 PSI (pounds per square inch) to function properly. A residential RO system drops the incoming pressure by 30-35% If you are starting out with 70-80 PSI, that is acceptable, but if the incoming water pressure is 40-60 PSI, there may be a problem. Volume and pressure are separate problems. You may have enough pressure to operate an ice machine, but not sufficient volume and it’s not as simple as adding another tank with plenty of volume and little pressure.
Sizing a reverse osmosis system is critical when you have multiple outlets, especially if one or more is an under-the-counter ice-maker. Most residential reverse osmosis systems are 24 to 50 GPD (gallons per day), which is not nearly enough for such an ice-maker. Additionally, production is reduced whenever the water temperature is below 77 degrees F, and whenever the pressure is below 60 PSI. In the real world, a 50 GPD reverse osmosis system in the Midwest may produce 20-25 GPD, when the demand may be up to 150 GPD.
there are solutions, and they do not have to be extremley expensive. One solution is to install a larger system, such as a 300 GPD system or a high production system, such as GE’s Merlin system, which produces 1/2 GPM of RO water. Another solution is to boost the incoming pressure with a booster pump or boosting the system pressure to 80 PSI with a Demand Delivery Pump. This type of system will provide plenty of high quality, great-tasting RO water, without running out! So, you can use RO water on ice machines (we install RO systems on very large commercial machines). They just have to be sized properly.
I was going to use my RO under sink unit to supply my fridge ice-maker.
I see you are installing on commercial machines, my concern is what is used inside the ice-maker, is it copper? Will the RO water leach the metals from the inside of my fridge fittings over a period of time? My concern is for the longevity of my fridge-freezer unit and not having to replace the ice-maker unit after a short period of time.
It is doubtful that a residential “line pressure” reverse osmosis system would reduce the TDS to the point of where it would leach copper. I think that this is a nothing to worry about. A home RO just won’t reduce the TDS to the point of where that would happen.
Hello Mark:
Just a note to say Hello from a former ARS buddy. I’ll be ordering a set of RO filters soon. Maybe you could give me a price break!!
Anyway, wishing you and your family a happy holiday season.
Take Care
Earl E. Ewart
How are you, Earl?
Give me a call.
So does the Merlin system reliably provide RO pure water at the 40 psi needed for the ‘fridge, with its low demand, even with TDS creep? How does the Merlin system prevent the fridge system being poisoned with TDS-creep water if it has very low demand, typical of ice and water only systems? Yeah, buy a flush tank — ok, but now you’re wasting 2 gallons of water every time you make ice, or make coffee, or even draw a cup of water from the fridge door.
The Merlin system, as great as it seems, NEEDS some sort of storage tank to improve its efficiency in real world situations. Its only efficient if you can draw down more than 10 gallons per cycle of its flush system. Otherwise it wastes more water than the cheaper units.
Bill,
You are not far off. The Merlin system is great, but it’s not something I would use for a home. In my opinion, a permeate pump RO is better, much better, because it wastes less water, supplies much higher pressure, virtually eliminates TDS Creep and costs a lot less than a Merlin. A Merlin is great when you need several hundred gallons of water a day. If you need but a few, look elsewhere.
We have a new everpur ro system and a new thermadore refrigerator which seem to be incompatible except for the first batch. The ice maker has been replaced and still no ice. I suspect it is the pressure/line freezing etc. What kind and where could we purchase an inline pump and or heater to make this compatible? We have the 3/8 inch blue tubing but I guess fittings on either side would allow for anything.
It is not the line freezing, but rather the fridge because you are not getting enough water volume and pressure. Your RO system is the problem. Most RO systems do not produce enough pressue and /or volume to operate an icemaker. I recommend a “permeate pump” RO for this application (100 GPD with a 14 gallon tank) to work effectively. Unforteneately the Everpure system doesn’t produce enough water or pressure for it to work.
Will an ice maker work with RO?
YES, If you have a typical residential RO it should have adequate pressure to make ice. If the pressure from the RO is not adequate there’s a couple of easy INEXPENSIVE ways to fix that.
1.) Simply increase the air pressure in the storage/ bladder tank. There is a little wiggle room here.
Be careful not to over inflate it, otherwise you will displace the room for your RO permeate water.
2.) Put two RO storage tanks (if you have room under the sink) in series. That will give you more than enough pressure. You dont need to purchase a commerical unit…
1. Increasing the air in the tank will decrease production, due to the increased backpressure, so it’s doubtful if that will help;
2. While 2 storage tanks will increase the volume, it will not increase the pressure, so you must first determine if it’s a pressure or a volume problem.
We just put in a RO system, which is in the basement. It is connected to the frig and no where else. There obviously is not enough pressure because I get 1/2-sized ice cubes, the tube feeder the cube tray keeps freezing up and water drips from the drinking water dispenser. I’m confused as to which side a booster pump should go on - the inlet side (before RO system) or the delivery side (between RO system and the frig). Also of note is that the run of supply tube from the system to the frig is approx. 25 ft. long. I appreciate any help! Thank you!
Judy,
I would need to know the following before I can properly answer your question:
1. What is your imcoming pressure?
2. What size is your RO system (Gallons Per Day)?
3. What is the size of your tank?
4. What size is the line to your fridge (1/4″ or 3/8″)?
Give me that information and I can give you an answer.
I have a residential RO system with a permeate pump to boost production. Since I have it in the basement, I had to put in a demand pump(1.7 gpm) to deliver water to the sink in the kitchen. When I tried to connect the RO system up to my fridge for ice and water, it caused the pump to cycle rapidly when I used the water dispenser in the door or if the ice cube tray filled. . The company I bought the system from suggested a 2nd tank between the pump and the fridge but the pump still cycles rapidly when the fridge water is used. Would increasing pressure in the tank stop this? I’m afraid of burning up my pump. I currently have it at 10 lbs PSI.
Steve,
You have several issues.
1. The pump is capable of delivering too much water. You really need a pump that delivers .6 or .7 GPM or a variable speed pump.
2. I would suggest only 5 psi in the second tank.
3. A better solution is to put a “booster” pump ahead of the Permeate Pump RO system as the Permeate Pump should deliver nearly the same prssure on the outlet side as you have coming in. A 1/4″ booster pump will work incredibly well in this application.
I have never had good success with a second tank. I would suggest a 75-100 GPD membrane in a permeate pump Ro with 3/8″ lines to all outlets and a 14 gallon tank. If that doesn’t solve your problem, then put the booster pump ahead of it and you will be amazed!
Mark,
I goofed. I just took a look at my pump again and it’s a .7 gpm Aquatec 5800 DDP. I tried putting more pressure in the tank but that just caused the pump to cycle rapidly sooner before the tank was full. Sooo, you’re suggesting to put 5PSI in the 2nd tank.
Also, with your suggestion, you said to put a booster pump before the permeate pump? I thought the permeate pump was to boost the output of the membrane and that would negate the need for a booster pump. At least that’s what I was told by the place I bought it from. What’s different between a booster pump and a demand delivery pump? Is there a pressure switch on the booster pump but not the latter? It just seems as soon as I get any drop in pressure due to usage at the fridge, the delivery pump kicks in and just cycles like crazy. If I tried the booster pump, I would imagine that the DDP pump that I have will not work? This is getting a bit frustrating….and expensive. I really appreciate your advice. I also saw one site had a pressure switch 30/60 PSI switch that mounts on the top of of a storage tank. If you’re suggesting 5 PSI, I would imagine that 60 would be a wee bit high. This DDP pump had a power draw of .3 amps@60 psi but I’m not sure if it’ll put out 60 psi or not. Thanks again for your advice.
If you boost the incoming pressure, you will automatically boost the outlet pressue. I have just found that most demand delivery pumps produce mixed results.
I would recommend trying both tanks first WITHOUT the DELIVERY pump and if that doesn’t work try a booster pump AHEAD of the permeate pump RO.
I recommed a pump like this:
http://tinyurl.com/62ndzz
P.S. Make sure you have 5 PSI in both tanks!
I installed my permeate pump R.O. in the basement. It’s about a 7′ run to the R.O. faucet. I also want to hook up my fridge/ice maker. That’s about a 10′ run. I’m thinking I should be using 3/8″ tubing to everything. What do you think?
Also the water is coming out of the faucet at a pretty brisk pace; the result is the water is cloudy at first due to the air bubbles. Should I reduce the pressure in the holding tank?
Thanks, Rob
Rob,
3/8″ is great.
The air in the tank should be 5-7 psi - no more, no less!
You get air bubbles when an RO is first installed. Drain the tank 3 or 4 times over a week and it should go away.