treatment chemical for steam boiler

I agree with @delcrossv but your question makes me wonder: What happened to the 8-way you added last year?

I think a quart is more than you need. Get a little book of litmus paper PH test strips from Amazon for like $5 and just add enough to get your PH to 10 or 11.

But more important, I would not drain the whole boiler every year. I just don't think there's any need for it. Have a look at this uncharacteristically short (for me) video I made where I didn't drain anything for a year and then drained just a little to see how much mud was in my boiler. Link to video

By not draining very much you will minimize the introduction of fresh, oxygenated water.

So I would just drain until the water runs mostly clear, then monitor the PH and add just enough 8-way to keep the PH at 10-11 or so.

You'll save a lot of money on 8-way too.

The damage might not be a bad as you think. I was in your shoes with my old boiler when I bought my house in 2017 and I never could get the water to remain clean, so I replaced my boiler in 2018, but after that I smashed apart the old boiler and it seemed to have a lot of life still in it.

Knowing what I know now, if I were you, I'd just keep that PH around 11 and drain 1/2 - 1 gallon once a year and see if the water starts to clear up. It could have many years of life remaining, like MANY.

Yeah check the PH with your current water in there. After adding a whole quart of 8-way I would suspect yours is at the top of the scale like mine was in the video above.

Remember, a lot of the mud you are seeing could be ironically from your annual flush. If you just flush a little to get the mud out once a year the water will eventually clear up. All the boiling action will eventually free up the rust and scale, and if it doesn't, no harm done. What does get freed up will fall to the bottom where you can drain it once a year.

I use treatment in my cast iron home heating steam boiler without issue.

I use Steamaster, but I guess that's not available anymore.

The only side effect I have had from it is erosion of the gauge glass. But I'd rather change that then a boiler.

A sort of general note… besides a comment that anything higher than 7 is probably fine…

With any treatment chemical, too little probably won't hurt anything. Probably won't do anything, either. Just enough chemical is OK, if you really need it (you may not). Too much chemical can be very harmful.

Some of our cast iron pots have rubber seals.

No idea.

It hasn't bothered mine. So far.

The main factor in water treatment is the material that the boiler is made of. There are different grades of cast iron based on the carbon content and added materials. There are different grades of mild steel based on the carbon content. This is why I warn people about using Surgex, 8 way, this way or that way. My Coop at my demand, replaced the contractor [40 years experience] who was servicing boiler because he was not properly treating the water according to the manufacturer. When the new water treatment company tested the water before they treated it, they found that the PH of the water was 2 levels off and a lot of corrosion.

Thanks. I wish I was there. I purposely put tons of extra 8 way in mine as a test and I couldn’t get it to surge, but my water was pretty clean

We tend to focus of pH (and, by the way, 7.5 is basic, not acid) as it's easy to measure and not all that difficult to buffer to pretty much any number you care to name.

It's not the only factor in boiler water chemistry, however, and if you are serious about controlling your boiler water chemistry you need to pay attention to — and be prepared to correct, if necessary — all cations and anions and oxidation/reduction potential, at the very least. Further, different uses require different (sometimes dramatidally different) treatment. Once through process steam boilers, for instance, often can only have the chemistry controlled through frequent blowdowns — while closed cycle power boilers run on distilled water and may require not only water chemistry treatment, but also volatiles to protect the steam side (particularly superheaters).

Residential and small commercial heating boilers should be closed cycle, but often aren't.

I think most additives are gimmicks. If you have a pretty tight system, that's not adding alot of make up water, it's unnecessary. The manufacturers of the additives will say other, of course Mad Dog

I second what @ethicalpaul says about pH! Out of habit….I always drained my boiler at the beginning of the season. There would be a bunch of mud and gunk at the bottom and the float type LWCO would drain a bunch of rusty, crusty liquid too.

I've been using Rectorseal 8-way for about 5 years now, just enough to get the pH to about 10-ish. At the beginning of this season I cracked the boiler drain and the LWCO drain to see if any dirty water would come out….crystal clear!

Keeping the pH to 10-ish on my boiler slows corrosion dramatically and keeps the water super clean.

Thank, @ethicalpaul — and to clarify my somewhat incoherent ramblings, I agree that for most residential systems — and, for that matter, many smaller commercial systems — simply doing two things… well, three! — is quite sufficient: making sure the pH is in a reasonable range — somewhat basic, if possible, but don't get carried away with the chemicals — and keeping dissolved oxygen as low as possible — which means adding as little water as possible, which in turn means no leaks and keeping vents in good working order — and bringing the system to a good boil if water does need to be added.

All that's required.

and bringing the system to a good boil if water does need to be added.

This one is still mysterious to me, and it's why in my experiment video above I only added de-oxygenated water (if that's a term) for a whole year.

It's a mystery to me because, it seems to me that if bringing the fresh water to a good boil after adding it was enough, then why do leaky systems rust out faster at all? Surely when the auto-feeder (or homeowner) adds water, it is because there is a call for heat and the water is too low, so the auto-feeder adds it, immediately followed by the boiler running and boiling the newly-added water.

So it seems that shouldn't even matter if, in fact, boiling the new water helped prevent corrosion at all.

But it seems that even if the new water is boiled (and it almost always is, I assert), that accelerated rusting still occurs.

And we never see a boiler with a hole rusted out below the water line, do we? (correct me if I'm wrong). If the oxygenated liquid water was the rust accelerant, wouldn't we see that a lot more often? (and the Hartford Loop sure wouldn't help in that case haha!)

We see holes up at the top of the sections, at least that's the only holes I've seen on this site. That's why people have to overfill the boiler to see if there's a hole rusted through, right?

So I would propose that this idea of "immediately boil after adding water" is not really a "thing". The oxygen seems to get released and does its damage while it's in the steam chamber above the waterline apparently before or as it's getting pushed out by the steam, with the damage probably assisted by the heat.

If you're still reading, please let me know what I'm missing here, thanks!

I don't know why, @ethicalpaul,yours didnt surge.

Mine runs on ounces per square inch and is very quiet. I tried 8-way and followed the instructions. It sounded like hell and I swore off the stuff for y e a r s because at 2am, my wife insisted that I do something. To get into my basement, I have to go outside in the cold dark.

I'm back on the stuff again but I use a fraction of what it calls for. Between you and @ChrisJ , I thought it would be worth another shot.

@SlamDunk I wonder if during your prior experience you used waaaaaaay too much 8-way. Don't follow the directions. Add as much as needed to get the pH to around 10, and that's it. Would be a good idea to get some good pH strips or a pH meter from Amazon.

My boiler holds about 10 gallons of water and 10 ounces of 8-way gets me to a pH of about 10.5 or so.

For what it's worth,

I've been using Steamaster since sometime around 2012. Since then I noticed over time the purple color fades and becomes almost clear. I've tried twice to add more without cleaning out the boiler and both times it caused issues because apparently even though the color faded the rest of the treatment was still in the boiler.

The point being, I personally don't add any treatment without draining the boiler, cleaning it and refilling. In my case I get away with two Steamaster tablets which is a fraction of the dose recommended on the bottle but twice the dose others use.

The reason I drain, clean and refill is because I do feel some of the treatment is "spent" over time. But, I may be totally wrong on that, it's just a guess. I've been getting lazy and only doing this every 2-3 years.

Besides an oxygen scavenger, there's a chemical in Steamaster that causes minerals to fall out of the water and allegedly fall to the bottom of the boiler where they sit until you drain the boiler. I feel both of these are beneficial especially with harder water like mine.

It's not that they're floating around.

They come out of the water and stick to the block like a plating. This additive stops that.