# Distilled or RO water



## Der Fuirmeister (Jun 18, 2010)

Anyone use distilled or RO water to fill their boiler?


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## heaterman (Jun 18, 2010)

Der Fiur Meister said:
			
		

> Anyone use distilled or RO water to fill their boiler?



Check with the manufacturer of your boiler. RO water can be quite aggressive to ferrous metals.


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## Der Fuirmeister (Jun 18, 2010)

heaterman said:
			
		

> Der Fiur Meister said:
> 
> 
> 
> ...



Will do.  Thanks


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## Medman (Jun 18, 2010)

Not just ferrous metals, but brass, bronze and copper as well.  I maintain dialysis equipment including high purity RO water systems, and we cannot use any materials for piping other than PEX or stainless steel for the pure water supply.  Even the drains have to be glass due to the water's ability to leach metals out of the pipes.  We had a cast iron drain segment completely disintegrate in 18 months - the walls of the 4 inch pipe were paper-thin when it was removed.

Regular tap water may be less pure, but it is more chemically stable and less likely to cause problems, especially if you add the proper chemicals to remove oxygen.  If you have high iron, calcium or dissolved solids then you will have to consider your options.  Some people here just transport water from a good source (like town water supply) in tanks and transfer it into their systems as needed.


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## Der Fuirmeister (Jun 18, 2010)

Medman said:
			
		

> Not just ferrous metals, but brass, bronze and copper as well.  I maintain dialysis equipment including high purity RO water systems, and we cannot use any materials for piping other than PEX or stainless steel for the pure water supply.  Even the drains have to be glass due to the water's ability to leach metals out of the pipes.  We had a cast iron drain segment completely disintegrate in 18 months - the walls of the 4 inch pipe were paper-thin when it was removed.
> 
> Regular tap water may be less pure, but it is more chemically stable and less likely to cause problems, especially if you add the proper chemicals to remove oxygen.  If you have high iron, calcium or dissolved solids then you will have to consider your options.  Some people here just transport water from a good source (like town water supply) in tanks and transfer it into their systems as needed.



"....If you have high iron, calcium or dissolved solids....."  We have all that.  I have another source for water that is better than our well water.  I'll use that instead of the water we have here.  


Thank you.  I appreciate your response.


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## in hot water (Jun 18, 2010)

You want DI or DM,  de-ionized or de-mineralized water.  RO and distilled is too aggressive as mentioned already.  Also expensive.

You don't want to use softened water either. 

DI or DM is available at any company that blends chemicals or glycols.  I've paid 10- 20 cents a gallon if I take my own plastic barrel.

The equipment looks like a like water softener without a backwash valve.  After so many gallons run through it the supplier switches the tank and re-beds them.  The one company I use, Rhomar Water in Springfield, MO gets the equipment from Culligan.

Some of the large mechanical contractors that work with glycols a lot, lease or own their DI tanks.  You may be able to rent the tank for a one time fill, just depends on what is available in your area.

DI or DM water should be used in all new equipment, but only after you run a good cleaning product through the system to remove grease, oil, flux, dirt, etc.

hr


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## DaveBP (Jun 18, 2010)

Well now you have me curious. 

What is it about RO water that makes it more aggressive to metals than any other clean water? Is it highly oxygenated from the process? 

Anybody know?


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## ewdudley (Jun 18, 2010)

DaveBP said:
			
		

> Well now you have me curious.
> 
> What is it about RO water that makes it more aggressive to metals than any other clean water? Is it highly oxygenated from the process?



It's just that since water is the "Universal Solvent", most 'clean' water from the environment will already be fairly well saturated with calcites, carbon dioxide, metals, and whatever, such that it doesn't have any appetite for dissolving the copper, bronze, lead, and iron in the heating system.  

But RO processed water has had a lot of its solutes removed, so it's ready to dissolve whatever it gets at first, namely the metals in the heating system.  It's possible as well that the RO water dissolves oxygen more readily before it gets into the system, which would aggravate corrosion by oxidation.

RO processed water can be 're-hardened' with treatments specifically formulated to make it optimized for use in hydronic systems.  But the same result can normally be achieved by adjusting the chemistry of less expensive water.

Cheers   --ewd


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## in hot water (Jun 18, 2010)

RO water needs to be piped with plastic or stainless do the "purity"  

Google RO, there is plenty of opinions about drinking RO water with 90% of the "stuff" stripped out of it.

I had an under counter RO for a while.  I didn't like the taste, or tastelessness of the water.  Carbon block handles my water just fine.  RO's waste about 3 gallons of water for every one they produce, also.

If you use RO water as Elliot mentioned, you need to put products back into it to protect the ferrous components of your system.  

Really the hardness and TDS are what coat HX surfaces and can cause a large drop in their efficiency.  Hydronic system inhibitors are added to some systems to keep the hardness in suspension so it doesn't coat the HX surfaces.  I still feel starting with good quality water is the best first step for a new boiler.

You wouldn't put used or dirty oil in your new car,  why put hard or high mineral water in you expensive boiler?

hr


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## heaterman (Jun 19, 2010)

DaveBP said:
			
		

> Well now you have me curious.
> 
> What is it about RO water that makes it more aggressive to metals than any other clean water? Is it highly oxygenated from the process?
> 
> Anybody know?



Simply put, it's the old law that says "nature hates a vacuum".  RO water contains nothing but hydrogen and oxygen. When RO water comes in contact with other materials, molecules of that substance (copper, iron or steel for example) try to fill in the void so to speak and break free of their normal structure causing eventual failure. Think of the RO water as a magnet for anything that doesn't exist in it, which is basically anything except H and O2.

When I have a problem with fill water I find a water treatment company in that locale and order demineralized water from them. Many times they will deliver it right to my job site in whatever size container I specify. It's really not very expensive at all when one considers the alternative consequences.


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## woodsmaster (Jun 19, 2010)

I've got high iron in my well water but its not really very hard. I normally use a softener to remove the iron. When filling my system should I bypass the softener and add an iron filter or should I buy water from another source. I'll need about 1100 gal.

Maybe I should quit using the spot free rinse at the car wash since it is R.O. water ? Dont want it to corrode my car.


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## in hot water (Jun 19, 2010)

I've struggled with iron water on my last two homes.  Treatment depends on what type, dissolved or insoluable, and what levels you have.  put some in a clear glass.  it is cloudy or brown right from the tap?  if it's clear but settles out after 30 minutes or so, it's probably dissolved iron.

Most basis softeners will handle up to 1 ppm of iron. Softeners can be built to handle up to 10ppm.  Softner salespeople sometimes over sell softeners and promise they will handle all iron problems.  Usually high iron will plug up the resin bed in short order and possibly an acid bath is the only way to clean the out. 

I ended up with an Iron Curtain on my first home due to high levels, I have a similiar technolgy on this home.  Both have a small air compressor forcing air (o2) into the water, then a contact tank, then a air removal device.  The tank backwashes every couple days and I get coffee or blood red water washing out.

I know instantly when the system has quit, the smell of rust and red color in glasses, laundry, etc.

High iron water will coat out the components of hydronic systems just like hard (calcium) water.

The key with water, any water is to have it tested to see what in in you water. and at what levels.  Water supplies can change.

Recently we had a bunch of wells contaminated in my area.  They suspect a dry cleaning business of dumping their solvents when they went out of business.  The well water smells like paint thinner or oil products.

hr


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