Rain water as boiler water

stevenknaub

Is rain water suitable for Independence IN-4 residential steam boiler? Rain is very low in Total Dissolved Solids, and having a PH of about 5.5, an addition of a small quantity of 8 Way Rectorseal woul bring it up to ph of 9.0.
My boiler is about 15 years old and I’ve used city water (very hard) and for the last 2 years used bottled spring water.

kcopp

A good option would be to install a inline water filter like this. It would de-mineralize the water for you.
http://www.axiomind.com/

gerry gill

Good question, I would feel it should be ok provided its ph was adjusted as you stated. I would for peace of mind have a lab run a water analysis on it just to see what is actually in it. Could be a nearby factory belching who knows up up into the air, with the rain picking it up. Just for peace of mind. But i like the idea actually.

stevenknaub

Thanks very much! John 3:16

hot_rod

good idea, I think i will run a TDS and hardness test next time it rains. It seems to work well for rinsing cars, less mineral spots.

Once the water is in the system, I would run the water test and buffer as needed as it will pick up some metals and minerals once you put it in, if it is low Ph, "hungry" water.

BobC

Rainwater is usually pretty clean but if it's been filtered through a roof and gutter with bird droppings - not so much. You can't know what the PH will be unless you measure it.

Bob

jumper

Virgin white snow is even better. Also for rinsing hair. Especially for folks who wash their hair with skunky beer.

Jamie Hall

The only thing to watch with pure rain water is that it's buffering capacity is usually very low. Which means that controlling pH may be a bit dicey -- you may need less additive than you might otherwise.

dopey27177

Why go thru ll the trouble of using rain water how many times are you going to have to put water in your boiler.)
If the water is so hard dont you think you need a water softner in your house.

The laundry comes out cleaner, you can use aluminum pots and pans and some times the hard water has a smell.

Jake

mattmia2

Rain water collects around dust particles so you will have whatever is in the air in the water along with whatever stuff it collected from the surfaces it fell on.

hot_rod

mattmia2 said:

Rain water collects around dust particles so you will have whatever is in the air in the water along with whatever stuff it collected from the surfaces it fell on.

Good point, hence the issues with acid rain.

The same hold true for water from the earth, whatever it touched or is in the air around look is inn the water. So I suppose which is the better source for the system.
rain water like ground water would probably vary from location to location.

Time was when I lived in the shadow of a Bethlehem Steel plants, the rain would eat away at the paint on the vehicles.

Most any issue with water can be fixed, sewage water can be drinking quality when put through enough processes.

DavidMitten

Rainwater is perfectly good water for many uses. It looks like you have measured the pH, which is pretty low, and therefore without any treatment that water is aggressive.
Is your comment about TDS a generalization abut rainwater? or did you do a TDS test?
What you need to know, is the total Alkalinity for your water. That will indicate how much pH adjuster you will need to use, and after adjustment, how stable the pH will remain.
You can do such test as a titration with a pool test kit, but if someplace in your area will test your water for free or a small fee, that is prob. better, since they do such work all the time, and will know the accuracy of their results.
Ask them how they run tests, since some are coarse, and others are more accurate.
If they a spectrophotometer, they can do a TDS test, although just testing conductivity will be close.
For TWS, you need a balance, and a bake oven or dessicator.
Once you know your water parameters, you can do some calculations to see how much additive you will need.
Right now you don't have enough information on how to treat the water.
I would use an in-line filter to remove any particulates.
If the water does have some acidity(such as acid rain) that is carbonic acid, and will be neutralized through pH adjustment.
If you need any clarification, just ask or post.
I am a former industrial water treatment tech, working in paint detackification, humidifaction, and cooling towers.

David

ColdInRI

DavidMitten said:

I am a former industrial water treatment tech....

David

Distilled Water ?

to DavidMitten, and any others here that know the particulars of water chemistry as it relates to CI boilers, copper piping and FHW systems...

my well water is very acidic, lots of pinhole leaks and larger over the years.. I just installed a new CI boiler last year and I was thinking of draining and flushing, then refilling the system with distilled water, would that not be a good idea ?

I'm assuming distilled water would be fairly neutral pH ?.. and certainly close to zero TDS or any other contaminants..

but not sure how "buffering capacity" works ?... is distilled water going through multiple heating cycles going to move up/down in pH or result in other adverse reactions ?

any input would be much appreciated

mattmia2

ColdInRI said:

my well water is very acidic, lots of pinhole leaks and larger over the years.. I just installed a new CI boiler last year and I was thinking of draining and flushing, then refilling the system with distilled water, would that not be a good idea ?

Is the system leak free? A system that adds makeup water because of leaks will corrode things quickly. Certainly water chemistry can do it too, but making sure you aren't adding fresh water and oxygen is the first step.

ColdInRI

Is the system leak free? ....

maybe not 100% leak free, but very close, at least until a new one breaks through
when I put in the new boiler, I isolated it from the supply with 2 ball valves in a row (belt and suspenders).. no auto-feeding makeup water

Jackmartin

Think of it like this: would you drink unfiltered rain water? The crap is full of junk from the air,bird poop, chemicals from air pollution and whatever crud it flowed over to get to your rain water tank
Flowers need rain water, boilers need water that has been chemically treated ,according to the boiler manufacturers instructions
I don't know what the parameters are for drinking water in the USA but in Canada it has to be certified clean, with no substances not suitable for human consumption I have never seen rain water have an engineer's stamp. Stay Well and Be Blessed Jack

DavidMitten

The first thing with water quality, is that you should have your water quality tested, then you will know what you are dealing with.
I responded to this post about using rainwater, because it is an environmentally conscious decision and I think that's good.
If you are filling a system, and are contemplating buying distilled water or R.O. water, why not just get some empty jugs and fill them with city water?
Municipalities ensure good water quality because it is of interest in maintaining and not corroding their infrastructure. They typically publish their water parameters too. A cheap, consistent and easy way to go.

Big Ed_4

All fresh water holds solids ... Steam heat does not use much of it . Small system maybe uses 5 gallons per year . It is designed to be a close system ..

hot_rod

> @ColdInRI said:
> (Quote)
> Distilled Water ?
>
> to DavidMitten, and any others here that know the particulars of water chemistry as it relates to CI boilers, copper piping and FHW systems...
>
> my well water is very acidic, lots of pinhole leaks and larger over the years.. I just installed a new CI boiler last year and I was thinking of draining and flushing, then refilling the system with distilled water, would that not be a good idea ?
>
> I'm assuming distilled water would be fairly neutral pH ?.. and certainly close to zero TDS or any other contaminants..
>
> but not sure how "buffering capacity" works ?... is distilled water going through multiple heating cycles going to move up/down in pH or result in other adverse reactions ?
>
> any input would be much appreciate

Purified water RO, distilled, or DI becomes “hungary” water low ph in the 6,s. It will go into the system and attempt to pull from the metals to balance to neutral, within a week you will see ph rise to more neutral.

In hydronic systems we add a hydronic conditioner which will typically buffer the water into the 8 range due to the chemicals they add. Conditioners contain O2 scavengers, film providers and ph buffers.

I suspect the steam system additives do a similar task, maybe buffering more alkiline into the 8 range to protect the iron above the water line.

ethicalpaul

But the most concerning of all is "hangry" water!

DavidMitten

So, Rob is correct about low pH water being known as "hungry water" or, if you are in Budapest, Hungary water!
The water wants to revert from such a pure form. It will pick up anything it can to go back to a natural state- that is water with minerals, impurities, solids, and so on.
To mitigate or lessen corrosion in a steam system, the additive is probably base such as Sodium Hydroxide or Potassium Hydroxide. Additionally, the package may contain a surfactant to keep junk in suspension, and a defoamer to lessen crossover. It may too have an oxygen scavenger.
There are two basic things to understand about water chemistry as it relates to metals:
1. If the water pH is high9.5-10.5, it is not so corrosive to steel and cast iron. When water pH is high like this and has heating and cooling cycles, then the minerals and impurities in the water will fall to the bottom or precipitate out of solution. This is why you see lots of white mineral deposits in the bottom of tea kettles.They have accumulated and precipitated(gathered).
2. If the pH is low, then it can easily rust metal, eat steel, and in another way eat noble metals such as brass, Copper and Aluminium. This process is called Solubilizing. In other words an acid solution or one with a pH 6 or below will cause those metals to become part of the liquid. This is how, for instance Cupric Sulfate is made(copper salts). Its that blue liquid they put in fountains to stop algae growth.
Someone posted a concern that rainwater contains bird poop and so on. Think about the fact that on Bermuda Island there is no drinking water. ALL of their domestic water is gathered from rooftops and collected in Cisterns. This is the case in many parts of the world. Just because something isn't done in America, doesn't mean it shouldn't be done.
I worked in a plant where the gray water(rain collection system) flushed all the toilets after going through basic filtration and UV purifier.

ColdInRI

so if you start with good, clean water, but it is "hangry", what type/brand additive(s) is best to use ?..... readily available in RI/New England area... something that doesn't require specialized instruments to use or properly dose... (reasonably affordable ?)

assuming a CI boiler, copper loop, closed system with no leaks, once the additives are in the water and proper pH is achieved, is it stable, permanent... last at least a couple years ?

before winter I need to reposition boiler and much of the loop tubing so a good flushing and refill is on the menu.. would really like to fill with something close to ideal, make my boiler and copper happy

nicholas bonham-carter

Are your steam pipes copper? Any leaks from them will be probably from the constant expansion and contraction as the system heats up, and cools down-mostly from the joints.—NBC