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How serious an issue is water quality?

   I work in the hydronics industry in Switzerland, where radiant heating is ubiquitous and where hydronic systems must conform to fairly strict criteria for water quality. Obviously the US is different.

   But in the States, is poor water quality a sleeping beast that people are sometimes unaware of, or is it simply not much of an issue?

   The company I work for produce a residential hydronic filter (<a href=""></a>) designed to protect hydronic heating systems from rust, limescale, and gasses.  Anybody in the industry is well aware of those problems, but is there a need in the market for a more effective, higher quality product?  Or are existing air/dirt separators doing the job just fine?


  • Mark Eatherton
    Mark Eatherton Member Posts: 5,837
    A sleeping giant...

    Water quality issues are REAL, and most contractors are not paying attention to them. Our older cast iron systems had very large water ways, so fouling was not a major issue. As those older beast die, and are being replaced with tighter clearance water wayed boilers, it is, and does become a problem.

    It is slow to raise its head, but it will become an issue eventually. Some high efficiency heat source manufacturers have begun addressing the need for water quality control in their installation manuals.

    It is also being addressed by the code authorities, but will be tough to enforce in the long run.

    It's not so much a case of "You got what you paid for", as it is a matter of "You DIDN'T get what you DIDN'T pay for, and you're NOT going to get what you thought you were in the way of comfort". Borrowed from Heatboy.
  • DanHolohan
    DanHolohan Member, Moderator, Administrator Posts: 15,273
    My thoughts, too.

    I've moved this thread to the Main Wall so more people can give opinions. I saw this product at AHR and was impressed. I wonder if there is a market for it in the U.S. Thoughts appreciated.
    Retired and loving it.
  • Harvey Ramer
    Harvey Ramer Member Posts: 2,217
    There is a market for it

    at my company. Water quality is a huge problem in the US and needs to be addressed in a meaningful way.

    I am curious, with the sorbox filter, is it still recommended to use a treatment such as Fernox?


  • Canucker
    Canucker Member Posts: 679
    edited February 2014

    I would think it would be a competitor to their filtration products but I would imagine it would add another layer of protection when used with inhibitors and the like. We use a similar system by dominck-hunter at my full time job to filter parts of our process flows during vessel transfers. I've often wondered if it could be used in a hydronic system, especially ones that contain iron, and this appears to answer "yes" to that question. Nice design, the filter mediums look easy to swap out when the time comes.

    I do have a question about the medium that removes all the dissolved minerals from the water. Would that not be a bad thing, kind of like adding deionized or RO water to the system.? Wouldn't the water remove theminerals from the metal in your system to try and re-establish a balance? We have problems measuring pH of our pure water because of the lack of minerals.
    You can have it good, fast or cheap. Pick two
  • Roger_at_SorbOx
    Roger_at_SorbOx Member Posts: 18
    SorbOx and chemicals

    To answer Harvey's question:

    In fact we recommend the opposite--that no chemicals be added to the system.  The reason is this:  SorbOx uses anodic (electro-chemical) technology.  Since both our sacrificial anode and chemical additives are oxygen scavengers, they would actually compete with one another, and prevent one another from working properly.

    As long as a chemical system is well maintained—with proper chemical dosing, regular flushing, etc.—as is the case in big industrial systems, it works well to prevent corrosion.  But in a residential system, that kind of strict maintenance just doesn’t happen, and without it chemicals can actually raise the conductivity of system water over time, as you have to keep adding more chemicals.

    SorbOx aims at solving that issue.  It includes a demineralization cartridge used for filling the system, so that you have mineral-free water in the system from the start.  Then it uses a sacrificial anode which continuously removes air, thus preventing corrosion.  The chemical process that takes place is not all that different from what happens using chemical additives.  But the difference is that SorbOx is self-regulated.  Oxygen will always react with (i.e. corrode) the anode first, leaving the byproduct in the chamber and letting oxygen-free water circulate through the system.

    I have heard of people using a conventional air-separator in conjunction with chemical additives, which work ok together since the air separator works mechanically (as opposed to electro-chemically).  But the cool thing about SorbOx is that it does both.  And it does it automatically.
  • Robert O'Brien
    Robert O'Brien Member Posts: 3,327

    Here on Long Island but it may very well be in other areas
    To learn more about this professional, click here to visit their ad in Find A Contractor.
  • Roger_at_SorbOx
    Roger_at_SorbOx Member Posts: 18
    Deionized water

    The question about deionized water is a good one.  If you filled a swimming pool with deionized water, it would have a tendency to take in oxygen and carbon-dioxide from the above air and "re-establish a balance", due to atmospheric pressure. 

    But that phenomenon only happens with gasses, not with solids.  There is no force that tries to re-establish mineral balance in the water (and raise TDS).  The water in the system will still have a tendency to re-establish balance in regard to gasses, which is why oxygen diffusion is an issue (CO2 diffusion doesn't take place because the molecules are too big to diffuse). 

    But to answer your question, No, demineralized water in a closed loop does not create a tendency for loop water to absorb minerals from the system components.
  • Harvey Ramer
    Harvey Ramer Member Posts: 2,217
    Next question.

    How do I get my hands on these filters? Are they available in a lot of different sizes? Are they meant to be piped as an inline bypass on large diameter piping? Are there any particulars on filter size or content based on system volume and water quality.

    I imagine a system should still be chemically cleaned and thoroughly flushed before a filter is installed? What is the normal maintenance on the filter, A. once the water has been stabilized B. till the water is stabilized C. a system with nonbarrier tubing or rampant oxygen ingression?


  • RobG
    RobG Member Posts: 1,850

    Do you use the filter first and then use the anode assembly or are they one unit? I only watched the video (english version), and it sounds like they are separate? It looks like a nice product if it works as advertised. How long has it been in use for?

  • Jamie Hall
    Jamie Hall Member Posts: 15,868
    Interesting problem

    and one which has been an issue with process and power boilers for a long long time -- there is a whole industry devoted to it, and an array of chemicals (some of which are pretty powerful and nasty stuff!) which are devoted to keeping scaling and corrosion and foaming at bay, in particular, but also controlling pH.

    If one is planning to treat one's boiler water, however, it is absolutely necessary to know what the chemical characteristics of the water are to begin with.  There is no one size fits all treatment.

    I cannot recommend either deionized or distilled water for a boiler.  Both are, in fact, corrosive until they establish an equilibrium with the boiler (and in the case of heating, piping) metals (a potential source of problems in wet returns in steam systems, though not a very serious one).  On the other hand, high hardness water can cause real problems with scaling, and measures taken to control pH and reduce hardness can be helpful.  High TDS water can cause problems with foaming and may also be corrosive, but the corrosion problems are related to exactly what ionic species are present and in what concentrations.

    There are, of course, additives which can go a long way to eliminating corrosion -- one uses them in automotive antifreeze all the time, after all! -- as well as additives which can help with scaling.
    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England
  • TonyS
    TonyS Member Posts: 849
    Deionized water

    I guess it all depends on the quality of the water to begin with. If you have a system with 300 gallons of water and 20 grains of hardness it would probably be prudent to remove the hardness but using a water softener would introduce a substantial amount of salt to the water which also harms stainless steel on the other hand using the water straight would introduce  close to 3/4 lb of calcium.

    If you have a system with 30 gallons of water and 10 grains hardness its going to leave you with less than 20 grams hardness in the system.

    De-ionizers are quite common for car washing and fish tanks, both 2 tank and mixed bed units and everyone on YouTube has a way of regenerating them.

    I think that it is a good idea to isolate the boiler and install flush valves like we do on tankless water heaters and clean the exchanger while we do the yearly service.

    As far as rusting pumps, I cant say I really ever had that trouble.
  • Bumpy
    Bumpy Member Posts: 1
    edited February 2014
    Water quality

    @ the supply house i work we carry a product line called fernox, customer feed back has been good as far as i know, its worth a look.
  • Roger_at_SorbOx
    Roger_at_SorbOx Member Posts: 18

    To answer some of the questions above:

    1)      Harvey—right now the only way to get a SorbOx in North America is to order through us (we’re happy to do that, but it will be pretty expensive due to shipping).  We’re looking for US wholesalers to work with, so hopefully the product will be more available soon.  But if you are interested in that, shoot me an email: [size=12][email protected][/size][size=12].[/size]

    [size=12]To your other questions, most of the info is available here: [/size][url=][size=12][/size]

    We have 2 different models (small and large) but they use the same piping size—1”.  The large model will do the job on just about any size home.  And it’s meant to be installed inline

    2)      Rob, yes the demineralization cartridge is meant to be used first.  Once the SorbOx is installed, you can close the top valves, unscrew the casing and put in the demineralization cartridge.  How long you run that will depend on the tap water quality you use, but it should be about a day.  Then the water will be demineralized and you can remove the demineralization cartridge and put in the anode, and it works automatically as loop water circulates through it.  Beyond that, the only thing you may need to do periodically (depending on the amount of sludge in the system) is close the valves, and rinse out the casing.  But that’s extremely easy.


    And the product has only been around about a year.  Right now we sell in Switzerland, Germany and Scandinavia.


    3)      Tony is exactly right about water softeners.  While they will neutralize calcium and cations, they don’t do anything about chlorides and sulphates. As far as I understand, they also don’t ever actually remove the calcium, etc. from the system; they just limit its ability to bind.  But I’m not too well informed on that subject.


    4)      Jamie, I’m interested in the equilibrium that you mention.  Our demineralization cartridge uses a resin, so it’s not distilling the water, but as far as I know, deionized and demineralized water are the same.  I haven’t really heard of anyone in the States demineralizing fill water (although it is now a requirement in Switzerland, and here I know that Viessmann includes a demineralization unit for filling water).  But in you experience have you seen corrosion occur because the water is lacking in minerals?  If there is any sort of equilibrium that takes place, I would be curious how it is explained. 


    Thanks for this feedback by the way.  And anyone can feel free to email me:  [email protected]
  • Roger_at_SorbOx
    Roger_at_SorbOx Member Posts: 18

    I messed up the link there.  Harvey, here is the proper link (to the SorbOx manual) to answer some of those questions:
  • Kevo
    Kevo Member Posts: 1
    King of my own throne!

    Water tests need to be done on ALL hydronic heating systems. We use Fernox and the test kit tests for Copper, Hardness, Iron, PH and Total Dissolved Solids (TDS). We have had great results treating heating systems and it has exploded on us. We can't keep the product on the shelf!
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