Does my boiler need chemicals?

Speaking from only my personal experience as a homeowner with an 80 yo steam system in Denver (where municipal water is slightly alkaline when not neutral), I don't believe treatment is necessary to prevent corrosion - ever. When I bought the house in 1994, I was advised by the inspector to replace the boiler asap simply because "it's old & inefficient." That was repeated every time a different HVAC guy came in for the annual inspection - which I ceased having done about year 5 - as a waste of time & money. When I sold the house this year, that system was still keeping me warm at reasonable cost, without any treatment other than canisters of Squick in the last two years. I had stopped calling HVAC guys whenever I was afraid the system was about to kick-it and bought Dan's The Lost Art of Steam Heating and Greening Steam to teach myself how to extend its life. It is a wonderful system, a monument to the Dead Men who built it on-site. Since moving to Vermont, I've heard nothing about steam heat except its corrosive qualities. I now have a baseboard system supplied by an estimated 30 yo "workhorse" oil-fired boiler that Dead River has deemed 87% efficient. I'll take that without complaint. I don't know what treatment may have been done to the water from the Wells River in the past 29 years, but there won't be any in-house in the future. I think too much is made of the perils of steam because there are few left who understand it. I also think it's unconscionable for an HVAC guy to install a scorched air system requested by a homeowner in the NE, much less recommend one.

if you use boiler treatments they need to be checked and maintained, using a test kit from the product manufacturer.

If the treatment caused failures or problems, either it was not installed in a cleaned system and flushed systems, soaps left over from cleaning, for example. The cleaners are aggressive, that's how the work so well, they need to be completely flushed.

Or it was not filled with good quality water, DI water. Or the inhibitor package was consumed and not checked and boosted.

Really O2 scavengers, film providers and ph buffers are the main ingredients, in the treatment chemicals, not really aggressive chemicals in any of those. But bad water quality can kill the conditioner pretty much from day one, same with site blended glycols.

It is a 3 step process to clean and fill correctly and it may involve several trips and related $$, which is why it gets ignored often, I think.

We did a repipe on a boiler room in a school. The previous “engineer” had advised the school to have a fibreglass tank built for condensate as they will not rot out. No one told the school, fibreglass does not like very hot condensate. The tank of course failed and little did we know ,they had the same” engineer” advise on 15 more schools and these wonderful tanks. We repiped the whole condensate, makeup water piping in the boiler room and I designed a stainless tank to take the place of the fibreglass unit. I am not an engineer and of course the genius with his fibre glass tanks was not even a tradesman, just a guy who could sell ice cubes to a polar bear. In the event you might think designing a new condensate tank is difficult, nothing could be further from the truth. Read The Lost Art it explains exactly how the procedure is to be done. I will admit ,I am a little better at math than most ,but that is simply because I have always been fascinated by the subject. No one will have trouble with the math for condensate tank sizing. However, we are talking water treatment. The fibreglass tank introduced a huge amount of resin into the system and the caretaker was due to retire in a year, ya know. He decided he was not going to waste his time on “ them stupid boilers”, each school here ,because it is so cold ,has two identical boilers installed to provide complete backup in the event of failure. We flushed out the condensate lines as best we could and then Dearborn came in and did the water treatment for the boiler plant. We felt confident that with Dearborn on the job ( they are really excellent) we would have no problems. I received a call from the new young caretaker ,he could not get the blowdown water to drain out of the two inch we supplied for that purpose. He told us the water goes into the two inch and then goes no where? We go down and have a look, thinking the youngster was wrong, nope, he was all too correct, The old caretaker had let these Weil McLean sectionals go with no water treatment from day one, and the fibreglass tank had been there from the beginning. Dearborn’s water treatment was making the layer of deposit on the walls of the cast iron sections slough off in sheets. The stuff migrated to the two inch and plugged the pipe solid. We had to take the whole thing apart and rod the deposit out. This happened the whole freaking winter, the youngster was fed up and if we were not being paid for each call ,I suppose we would have been too. The “ engineer” also specified pumps that had an open seal. Yep, have to keep the seals cool, so he had them set to 20 drops a minute. I will not insult your experience, we all know what that did for the system. This “ engineer” had a nick name ,Brian Wonderful ,because he was always saying the word wonderful all the time. The same school division employed a water treatment outfit before Dearborn came on scene and over the three years they had this genius they repiped — no exaggeration —— 30 firetube boilers all over 100 horse power. In our opinion when it comes to commercial water treatment, get someone like Dearborn, we do not take chances. All the best Jack