Can I use reverse osmosis filtered water in a one pipe steam boiler? (Good answers)

daveo

The water company shut off the water this morning to dig up the street without any notification. My boiler just hit LWCO. I have about 10 gallons of reverse osmosis filtered water and no idea when the water company will restore service.

Can I use the filtered water in the boiler? I expect so, but want to check.

Jamie Hall

Eh? I beg to differ, @Youngplumber -- nothing wrong with reverse osmosis water. The stuff isn't cheap, but it's fine -- in fact, I have often suggested it in cases where the normal feed is very hard.

Distilled... somewhat more aggressive, and I'd avoid it unless there's no substitute. Ion exchange softened? No way.

WMno57

@Jamie Hall Whats wrong with distilled water? Easy to buy for a Buck a gallon at Walmart. Once mixed with the remaining water in the boiler would it still cause problems? If it needs the PH raised that ought to be easy. Are there any household chemicals that work to raise PH in boilers? Baking soda, Ammonia?

Jamie Hall

It's as much a matter of what isn't in the water as what is. Distilled water has nothing to speak of in it -- except water. And pure water is about as close to a universal solvent as one can get, oddly enough. It may be slow on some things, but it will get there. So-- distilled water needs to have some buffering compounds added to it if it is to be used for, say, a boiler. Reverse osmosis water still has some buffering capability -- but is more corrosive than plain ordinary tap water. Your comment on water supply use is well taken. RO water is sometimes used -- particularly for hard or brackish waters -- to dilute the total dissolved solids to a more acceptable level.

nicholas bonham-carter

There is probably a difference between the reactions to RO water between a boiler, and a human being -OK for one, but not the other, (reduction of electrolytes in the blood).
More important is the question of where the OP's water has gone to leave his boiler in such a water depleted state.--NBC

Jamie Hall

WMno57 said:

@Jamie Hall Whats wrong with distilled water? Easy to buy for a Buck a gallon at Walmart. Once mixed with the remaining water in the boiler would it still cause problems? If it needs the PH raised that ought to be easy. Are there any household chemicals that work to raise PH in boilers? Baking soda, Ammonia?

Nothing wrong with it at all if it's mixed as you suggest. See my note above -- the other water will provide the buffering capability. I'd not use ammonia as a pH control, as it will disappear quickly. Baking soda will work, but use it with caution -- it's very easy to overdose. There are commercial products which are more expensive -- but are much better buffer systems and often have additional corrosion inhibitors or oxygen scavengers as well.

ethicalpaul

Spring water by the gallon, or Aquafina by the case is easy to get. Or some gallon jugs filled up at a friend's spigot

EdTheHeaterMan

I'm not getting it. RO is a filtering process. So, does it chemically change the water? Or does it just take the crap out of water? (CRAP is the technical term for Chemicals, Refuse And Particles.)

Is there so much missing from the RO filtered water that you can't use it safely? Can't you just add that needed CRAP back into the water?

Maybe I need to take a course in the right CRAP needed in water. I'll need to sit on the Crapper and think about this more! I'm going to the Throne Room and bringing a load of CRAP to read.

Yours Truly,
Mr.Ed

luketheplumber

Could you possibly have enough water remaining in your pipes to get it going. Perhaps you could get enough water by opening the highest faucet and drain down enough water from the domestic system to get you going?
I'm just an apprentice so please don't try this unless someone else backs me up in this idea.

WMno57

luketheplumber said:

Could you possibly have enough water remaining in your pipes to get it going. Perhaps you could get enough water by opening the highest faucet and drain down enough water from the domestic system to get you going?

One of the advantages of the old fashioned stand alone water heaters is in the event of a water outage, you still have 40 gallons of water. Just one more reason why I am not a fan of tankless water heaters.

EdTheHeaterMan

luketheplumber said:

Could you possibly have enough water remaining in your pipes to get it going. Perhaps you could get enough water by opening the highest faucet and drain down enough water from the domestic system to get you going?
I'm just an apprentice so please don't try this unless someone else backs me up in this idea.

leave it to the new guy to think past the experts and get to the obvious.

daveo

@Jamie Hall, Thanks, that is what I was thinking (re RO) and wanted to make sure with people that have a good history in this.
@ethicalpaul another good suggestion, Thanks.
@EdTheHeaterMan I'll have to study that
@luketheplumber I just realized that the feed comes from the water heater (NOT tankless) so that might have worked. BTW, make sure to read the @DanHolohan books (also available on Amazon as ebooks) and articles written on this site. I found out that I now know more (on some topics) than the PSE&G guy they sent to estimate my boiler replacement. "What is this EDR stuff you speak of?"
@WMno57, Mine is, in fact, a 40 gal tank.

Thanks all! I've edited the subject to remove "URGENT" because your answers have helped me get the heat back on. Now, let's hope they get the water turned back on. It's COLD outside!

luketheplumber

@daveo Thanks I've been buying and reading many of @DanHolohan 's wonderful books and I can't thank him enough for all they have taught me.
BTW What method did you end up using to refill your boiler?

HomerJSmith

A reverse osmosis sys removes solids and chlorine in the water unless you have special filters.

If you are going to raise the PH use Potassium Hydroxide and measure the PH of the water as you add it. I measure it per gal with a gram scale.

If you have a conductance low water sensor on your boiler you need a certain level of Total Dissolved Solids and distilled water don't have any.

Jamie Hall, I thought gasoline was the Universal Solvent. hmmm

Jamie Hall

CocaCola, @HomerJSmith !

Reverse osmosis removes the CRAP (I love that, @EdTheHeaterMan ! The nice thing is it does also remover a good part of the various ions in the water -- and the organic molecules -- in addition to what would be taken out by a filter. But not quite everything. So it is a little less corrosive than straight distilled. It can be controlled, too.

daveo

@luketheplumber, I started with putting what I could from "water in the pipes" and that got me some heat. Thanks!

About an hour after that, they must have gotten stuff buttoned up and started flushing the lines because I heard the toilet start to fill slowly, so I scooted down to the boiler and topped it off (just over the line).

neilc

so about that boiler,
is it leaking dry, every day ?

daveo

@neilc, the boiler is cracked along the top and I sealed the part I could get to with JB Weld. It is still leaking some steam, but not as much as before the JB Weld. I do now manage to get up enough pressure to hit Pressuretrol cutoff (at 2 psi) during the morning and evening cycles. I add water a couple of times a day to keep it above LWCO, but it usually hits it before I get up in the morning.

You do what you can to avoid freezing...

I'm getting quotes on replacing it. It is an old Utica and a bit oversized (in addition to being cracked)

neilc

lower the Ptrol even more,
as low as you can get it,
you really don't need 2 psi,
0.5 - 1.5,
less pressure to leak out,
and still able to heat

PerryHolzman

From a guy who's spent a lifetime dealing with commercial and power plant boiler water chemistry.

The short answer: In a pinch... use any reasonably clean water. A 1 time small quantity of most any water is not going to kill a boiler.

Long answer: Actually - RO water would be great for heating systems and boilers as long as the ph is basic.

The less stuff (crap) there is in the water - the better for the boiler. Less to plate out, less to plug things up. The chance of "pure" water dissolving your boiler is just a myth (most people on this forum had no idea of just how pure we have to have water in a 2400 PSI boiler - we're talking allowable on the part per billion level - and there are power plant boilers that are 40+ year old and will run for another 40 (if the rest of the plant will make it) - with no signs of dissolving due to pure water. Yes pure water is almost the ultimate solvent. But, it takes many years to reabsorb stuff from exposure to iron, steel, or even other hard deposits.

In fact, the purer the water is... the better it is for the boiler.

Reverse osmosis typically removes 90- 95% of the contaminants from water depending on membrane technology being used and its condition. It's far better for your boiler than tap water.

The one potential issue is that simple reverse osmosis will make the water it comes from either a bit less basic, or even acidic if it was nearly neutral (demilitarization can leave water acidic as well). This is a natural result of removing some of the minerals.

You do want the overall water in the boiler to be basic so it does not dissolve the boiler from acid attack.

Adding a small quantity of slightly acidic water to a boiler full of basic water will be OK, the rest of the water will neutralize the new water.

If its going to be a constant feed. You should add a commercial boiler inhibitor routinely - which will keep your boiler basic. A once a year boiler treatment will work for most home heating boilers.

I would expect that the RO units in grocery stores, Wallmart, etc. to use filter to take out large particles, an activated filter to remove chlorine from the water, and then run the water through the RO membranes, which are changed periodically (and potentially cleaned and reinstalled at a later date).

A larger commercial RO unit will use a inlet filter and then inject sodium bisulfide to kill the chlorine (a lot cheaper than carbon filters for large quantities of water), run the water though either a 1 or 2 stage RO (depending on purity needed), and may run the water though a stripping tower to get rid of most of the CO2 in the water to reduce acidity. If that is not pure enough that water is then fed into a sodium hydroxide and hydrochloric acid based deminalizer system (or rental bottles for smaller application processes) to produce ultra-pure water (which is what chemical plants, industrial plants, and modern high pressure power plants do).

Note 1: I personally specified and installed the 1st ever RO based water treatment plant in a power plant in the USA with this system in the very late 1980's - so I would not have to deal with truckload quantities of hazardous chemicals... and the required safety program and equipment then being newly required (I actually used rental deminerlizer bottles that were recharged offsite by a private company): Huge savings in safety and training cost as we totally eliminated very hazardous chemicals from the plant).. Once the power industry saw it worked... it became the standard for all retrofit and new water treatment plants in the power industry. I borrowed it from the electronics industry.

Note 2: The resin in a salt based water softener is often the exact same resin an a hard acid/hard base demineralizer system. The difference is that Sodium Hydroxide and Hydrochloric Acid exchange an OH- ion and H+ ion for the various minerals and ions in the water. The remaining OH- and H+ then combine to form H2O - water; that's an elegant solution. Of course, major chemical safety precautions and clothing are required for multiple people and you have to be set up to handle a major spill of the entire contents of any storage tank or delivery truck if you are buying in bulk.

In large commercial and power plant boilers we have chemical feed pumps that add precise amounts of chemicals to the feed-water system after the make-up water points to maintain our feed-water and boiler water chemistry basic and in a very tight band.

The thing you wish to avoid is salt based water softener water. That does not reduce the level of contaminates at all - just exchanges the worst stuff for sodium and by the nature of the process adds chlorides as well. In almost all cases - your tap water would be a better water than salt based water softer output. Na+ and Cl- are fairly nasty overall.

Finally, dissolved oxygen is actually your worst concern once you have adequate water purity and basic water. No matter the water source - adding water will add dissolved oxygen unless you have stripped it out or treated the water to remove it (which is what is done in commercial and power plants).

Perry

jumper

>>Finally, dissolved oxygen is actually your worst concern once you have adequate water purity and basic water. No matter the water source - adding water will add dissolved oxygen unless you have stripped it out or treated the water to remove it (which is what is done in commercial and power plants).<<

I'd add that pure water doesn't stay pure in the boiler so unless there's too much pure makeup......
Whether it's oxygen or CO2 or just pure distillate facilities with horizontal condensate lines have problems. Some operators decide to not recover condensate with the excuse that distillation is not that more complicated than steam stripping.