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Discussion Starter · #1 ·
As you all know, many components in a hydronic (water based) heating system are made out of steel or iron. As the water is circulated, it gives off it's oxygen through air purgers, or air seperators, and future corrossion issues are minimized in the heating system as long as very minimal make up water is added throughout the life of the heating system.

But doing service calls/dealing with older systems, you always notice the water is "dirty," or "black." There is definate particulate in the water. With the fragility of some sensors located in boilers or other components, I always question this. For example - when you see a system that has a stainless steel boiler/heat exchanger, copper or plastic piping, brass or bronze, valves and components (e.g. air seperators, pressure relief valves, etc.), I have a hard time wondering why you wouldn't spend a little bit extra and put in a a potable tank instead of a non-potable expansion tank, as well as bronze or stainless steel pumps instead of cast iron versions. Yes the "little bit" part could be "a lot," but still...

Also, no matter what, while the pex pipe we use for radiant floors technically does have an "oxygen barrier," it technically can still has some oxygen/air permeation through it.It has only met the standard for oxygen barriers, not a complete oxygen barrier. The only true oxygen barrier "plastic" pipe would be Kitec.

I am not talking about putting water into the system that is distilled with no minerals as some components like low water cutt offs require minerals to sense water, but what is your opinion or experience on non ferrous versus ferrous metals in heating system and subsequent reliability?

Also, do any of you use Dirt Seperators or strainers in your heating systems upstream of a boiler and how well do they work in your opinion?
 

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see quote

As you all know, many components in a hydronic (water based) heating system are made out of steel or iron. As the water is circulated, it gives off it's oxygen through air purgers, or air seperators, and future corrossion issues are minimized in the heating system as long as very minimal make up water is added throughout the life of the heating system.

But doing service calls/dealing with older systems, you always notice the water is "dirty," or "black." There is definate particulate in the water. With the fragility of some sensors located in boilers or other components, I always question this. For example - when you see a system that has a stainless steel boiler/heat exchanger, copper or plastic piping, brass or bronze, valves and components (e.g. air seperators, pressure relief valves, etc.), I have a hard time wondering why you wouldn't spend a little bit extra and put in a a potable tank instead of a non-potable expansion tank, as well as bronze or stainless steel pumps instead of cast iron versions. Yes the "little bit" part could be "a lot," but still...

Also, no matter what, while the pex pipe we use for radiant floors technically does have an "oxygen barrier," it technically can still has some oxygen/air permeation through it.It has only met the standard for oxygen barriers, not a complete oxygen barrier. The only true oxygen barrier "plastic" pipe would be Kitec. Or Fosta PEX.

I am not talking about putting water into the system that is distilled with no minerals as some components like low water cutt offs require minerals to sense water, but what is your opinion or experience on non ferrous versus ferrous metals in heating system and subsequent reliability?

Also, do any of you use Dirt Seperators or strainers in your heating systems upstream of a boiler and how well do they work in your opinion?
 

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I do work with a few 1914 boilers, control failures only K.I.S.S. they are dirt simple. the newer units I have worked with are all C.I. boilers and have yet to run into any issues from water quality. I do not work with or install any condensing boilers where water quality could become an issue but even there the water side of the boiler is still pretty simple. in an entire new system i don't see water quality being an issue as much as just different metals and grounding.
 

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On newer mod/con boilers of anything that is really low mass, we'll use a wye strainer on the return as well as a Caleffi dirt seperator. We bill in a service call within the first month to clean the strainer and seperator and see if we can set up a maintenance plan from there. I've been leaning away from pex for heat loops and have been using pex-al-pex in some instances. The aluminum laminated in the middle of the tubing provides a complete oxygen barrier.

It's amazing the amount of heat transfer that you lose with sediment inside the heat exchanger, fire side or water side.
 

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Never had issues with "dirty" water either. The biggest issue we have seen in the past has been with radiant loops in poly b. Those systems have by far had the most problems.

An airtight system (with proper air control) with ferrous metals has been proven over time to be still the most reliable setup.
 

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Discussion Starter · #9 ·
I've seen some PolyB Heating Pex (with O2 barrier) that had issues with overheating and even blowing the transition fittings from pex to Polyb that we used.

I just have a hard time wondering why we put all this money into a system with Copper, Brass, and Stainless components, then huck a few cast iron or steel parts in there. Wouldn't cleaner water/non-ferrous metals only help?
 

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Again, every system that I have ever run across that had dirty water probles was because of either non-barrier plastic tubing or a leaking system that is constantly having make-up water added. Take a look at old steam systems. We service some boilers that are a good 70 years old and are still operating just fine. If you think you have an issue though, by all means install a dirt separator. There are alos rust inhibitor porducts that work.
 

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Discussion Starter · #11 ·
Again, every system that I have ever run across that had dirty water probles was because of either non-barrier plastic tubing or a leaking system that is constantly having make-up water added. Take a look at old steam systems. We service some boilers that are a good 70 years old and are still operating just fine. If you think you have an issue though, by all means install a dirt separator. There are alos rust inhibitor porducts that work.
I'm not saying I personally have an issue or that I encounter it a lot. It's just an honest question/worthy discussion.
 

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If I remember this right, there is an issue of Idronics put out for free on www.caleffi.com, that addresses hydronic separators and dirt collectors.

If you're not using hydronic separators and delta t, variable speed circulators you are still in the dark ages. :thumbsup:
 
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