Signs a Boiler is Nearing the End of Its Life???

AdmiralYoda

I have a somewhat generic question on how you can tell a gas boiler is nearing the end of its life. I have a 28 year old boiler and a few years ago a friend of mine who is a plumber serviced it. He wanted to replace a part for it and had some difficulty getting the part. When he did get it we installed it and he said something along the lines of "You might want to think about replacing your boiler, its getting near the end of its life and parts are getting harder and harder to find". It looks its age as well with some rusty inspection panels, etc.

But then I hear stories of people with 50+ year old boilers working just fine. So when do you guys judge that a boiler is dying? When there is a puddle on the basement floor? I'm just wondering because new steam boilers aren't much more efficient than the one I've got. It says 81.6% AFUE on it. Provided its running right, I'm not going to get much better efficiency replacing the unit just because it was old.

Mark N

My original boiler lasted 75 years. Nothing wrong except it was an old coal boiler converted to run on oil. Well maintained boilers should easily last 50 years. The problem is feed water. Feed water brings in dissolved oxygen. That oxygen rots out the boiler. Also feed water with excessive chlorides in it. All leaks need to be repaired. Water usage should be only ounces in a month, not gallons a week.

Mark N

Post some pictures of the boiler. If you have a conventional LWCO that needs to be blown down weekly, you need to boil the water that is added to replace it immediately to get rid of the oxygen. Boiler water over time also has a tendency to become slightly acidic because of reabsorbing carbon dioxide forming a mild carbonic acid. PH levels need to be checked regularly.

AdmiralYoda

Good to know. But also points out the problem that I've had to add excessive make up water since I've been at this house. One radiator leaks. Our water is high in chlorine too. Great.

Fred

My boiler is almost 32 years old and I hope it lasts 50+ years. For me, End of life is usually characterized by a repair, to the boiler, that will cost at least 40% to 50% of the cost of a new boiler where I know the repaired boiler is not likely to have a repaired life of at least 50% of the estimated life of a new boiler. OR, new boilers have effeciencies or benefits that I want to incorporate into my system.

AdmiralYoda

I do drain the water out of the LWCO and from the bottom of the boiler regularly "until its clear". Is that considered being "blown down"? I typically do this once the boiler has cooled.

Should it be done when hot and boiling instead?

I also completely drain and refill the boiler a number of times during the beginning of the year as lots of sediment and rust tends to drain back into the boiler after the first few times of use. Not a good idea?

Fred

That is considered a "Blow Down" As a Test, What you do want to do occassionally is blow it down while the boiler is running. If the LWCO is working properly, it should shut the boiler down in a couple seconds and the boiler will restart when you close the blow down valve.

Whenever you drain and refill the boiler, you should make sure you do it when you can run the boiler and bring the water to a boil to burn off any excess oxygen. That oxygen is what kills the boiler block. I wouldn't drain and refill more than once a year at most. Flush the boiler out during that single drain and then flush any residual sediment out through the regular blow downs or the occassional opening of the boiler drain until that mudleg runs clean.

vaporvac

P.S. Chloride is different from chlorine, so you may not have problem there. The main question is "why are you adding excessive make-up water?"

Fred

She says she has a radiator that leaks. It would make a lot of sense to find a good used radiator and replace the leaking one.

AdmiralYoda

I apologize for starting multiple threads on different issues....they all seem to end up answering the same questions!

I have one radiator that has a light leak between two of the sections. I'm pretty sure it is a push nipple and not a threaded one as there is threaded rod holding the radiator together.

If I get ambitious I will take apart the radiator and see whats going on. I doubt I'll be able to repair it but hopefully can find a replacement nipple. I've seen a few sources on here so hopefully I can source a new nipple.

That leaking radiator is the only source I can think of that is causing me to add water once per week during the worst of winter. All of my pipes are above ground and accessible.

I'll probably start a new thread in the coming days with plenty of pictures, diagrams, lengths, etc so you guys can pick apart my system so I can make improvements where needed. Thanks!