Update in comments:100yo boiler crack (not cracked)

SkyBluePink

I just found this site and have spent days here learning how our home heating system works.
We have a 1921 A.D. Dennison, Cleveland, OH, gravity hot water boiler.
It developed a crack and we can keep everything dry by keeping the pressure low.
Can the crack be fixed? Can we live with the low pressure indefinitely?
Thank you all for keeping this site informative and fun.

Ironman

Sorry, but that's wishful thinking. It's new boiler time.

Check the contractor locator above for one near you.

MaxMercy

SkyBluePink said:

Can the crack be fixed? Can we live with the low pressure indefinitely?

If it's a crack and not a rust through (have you seen the crack?), you can attempt a weld if it's in an accessible position, but as Bob said above, it's boiler time. Hey, 100 years is a good run...

If you want to hold off replacment until the weather gets warm and if the leak gets worse even at low pressure, then you can add stop leak (Hercules makes a liquid) which will buy some time.

You'll also use a lot less oil/gas with a modern boiler.

SkyBluePink

Never thought about it rusting through. When I looked for the crack, I don't actually see one.
I mentioned it has been dry for awhile. Upon further interrogation of the husband, a bit more info has come to light. When it was wet, the asbestos came off in a chunk. The boiler looks rough. Why would it stop leaking on its own?

EBEBRATT-Ed

The leak may slow or stop when the boiler is warm and the metal expands and leak more when cold.

Look, there is no saving it, bitter news I know. Call around and get the right contractor......that's the most important thing. And don't take the cheapest price

Check "find a contractor" on this site

Intplm.

Time for a replacement.

Not a great fix, and certainly not permanent. But to buy yourself a little time, you might be able to use something called "boiler seal". The stuff can, but does not always stop boiler leaks.

It's time to have a one on one with a professional.

SlamDunk

You will pay a new boiler off in one or two heating seasons with fuel savings while increasing the value of your house. It's a win-win.

A 1921 anything has got to be a fuel guzzler.

SkyBluePink

It is so very cool to learn how these work. I suppose nothing in today's market is like this.

I can only guess our thoughts were to wrap the boiler in a hot water tank blanket when we saw a not-too-smooth asbestos coating.


Inside the fired-up boiler, corrosion is visible.


We took down a wall to get at the ginormous marshmallow. Evidence of leakage is obvious now.

SkyBluePink

Using the locator above, we found a single but very highly esteemed contractor in my area with a 2 month waitlist.

SlamDunk

There are very good reasons why there is nothing like that in today's market. That has to go to the dump.

EBEBRATT-Ed

@SkyBluePink

Your pictures don't show any corrosion or water leaking. If the combustion is safe (no excessive Co) and no water leaking keep running it no panic. 1920 boiler, yes it does need to be replaced. Budget for a replacement and most important find the right contractor

SkyBluePink

**Update: We learned a number of things.
It seems most likely that one of the pancakes has corroded and we see the slow leak from there. We have been bleeding incorrectly. We should have been draining the expansion tank regularly. The feed valve was defective.
Our flue gas numbers: 84ish% efficiency (!), CO is 220-something ppm, CO2 is 7.4. The numbers are what I remember-what they measure may be mixed up.

So we have a choice: not broke, don't fix it OR replacement is inevitable so may as well.

In the meantime, we replaced the feed valve, discovered the expansion tank drain is clogged, bled the rads correctly. Thankfully we have good weather and can address these without freezing.

SlamDunk

Replace it. You are on borrowed time and have already learned there is a two month waiting list. You may as well get on it and hope you don't have complete failure before then.

EdTheHeaterMan

if it ain't broke???

you need a new boiler. it IS BROKE

mattmia2

That water heater blanket isn't a great idea either. It is not noncombustible, or at least some parts of it are combustible like the facing and the binder in the fiberglass so it isn't designed to be one something like that boiler where numerous parts of it get hot enough to start something on fire.

SlamDunk

You should have both a smoke detector and Carbon monoxide detecter near it. Here is why: as @mattmia2 said, your insulation shell is melting. And, modern burners emit carbon monoxide in the 0 to 5ppm. You have around 200ppm. And, your boiler is leaking enough to melt plastic so, your health and safety is at risk because that CO is escaping into house.

MaxMercy

EdTheHeaterMan said:

if it ain't broke???

you need a new boiler. it IS BROKE

Yep. It's leaking - the fact it's not leaking from a crack specifically changes nothing.

mattmia2

Unless it is leaking form a relief valve because the expansion tank was waterlogged, or an overflow form an open tank.

But unless you are super strapped for cash I would replace that either way, there are lots of issues there that fixing them would only be a band aid for the inevitable.

EBEBRATT-Ed

Yes. 220 Co is too high, Co measured in the flue gas should be below 50 and anything over 100ppm is considered unacceptable.

Co is very dangerous

SkyBluePink

EBEBRATT-Ed said:

Yes. 220 Co is too high, Co measured in the flue gas should be below 50 and anything over 100ppm is considered unacceptable.

Co is very dangerous

Possibly, because I am still learning, I mixed up the CO and CO2 numbers.

SkyBluePink

SlamDunk said:

You should have both a smoke detector and Carbon monoxide detecter near it. Here is why: as @mattmia2 said, your insulation shell is melting. And, modern burners emit carbon monoxide in the 0 to 5ppm. You have around 200ppm. And, your boiler is leaking enough to melt plastic so, your health and safety is at risk because that CO is escaping into house.

It is very possible that I mixed up those 2 numbers. CO detector actually detects nothing, but I agree about the blanket...still learning!

SkyBluePink

We are fortunate to approach this issue in a dry and warm house--not pressing our luck.

I have learned so much from you, considering becoming a groupie. A six-pack to you all, with our deepest gratitude!!

mattmia2

There are complications about how the UL standard for CO detectors is written that means they don't alarm until there is a fairly significant amount for a significant period of time. Some of the one with LED or LCD displays can indicate lower levels, sometimes only if you push a button.

SlamDunk

I believe you have the CO correct. If anything is mixed up, it would be O2 with CO2.

As long as you have something to warn you, regardless of its sensitivity, it is better than nothing.

Still, there is nothing about your boiler worth saving. It is a fuel pig that should have given up its ghost in 1950. You should think of it as a zombie. a living dead.

SkyBluePink

@SlamDunk Would it surprise anyone that our average winter gas bill is just under $100?

ChrisJ

If I bought a house and it had a decent 1920s-30s three pass boiler in the basement, I would probably hesitate replacing it until I had to. At least if it was setup well and seemed reasonably sound (no leaks etc).

But that style boiler..........with whatever it's going on for insulation. That needs to go. That's about as appealing as an outhouse breeze.

You're talking about something you depend on during the winter. Something you literally cannot be without.

STEVEusaPA

There's no way that's CO2 7.4 and your efficiency is 84%. There's also no way it's 84% in general, which if true is only the burner efficiency, not total system efficiency which is at best 50%.

ChrisJ

STEVEusaPA said:

There's no way that's CO2 7.4 and your efficiency is 84%. There's also no way it's 84% in general, which if true is only the burner efficiency, not total system efficiency which is at best 50%.

Isn't combustion efficiency calculated by the analyzer using the difference between calculated flame temperature and exhaust temperature?

STEVEusaPA

Not just that. @Jim Davis could explain it much better.

SlamDunk

SkyBluePink said:

@SlamDunk Would it surprise anyone that our average winter gas bill is just under $100?

Very surprised!

Because I used to have two houses with similar systems.

One was a 1920 oil furnace (1800sqft house) in NYC and the other was a 1930 (1000 sq ft house) steam boiler in NC. The 1930 boiler most resembles what you have.

The fuel bills were GI-normous when compared to the upgrades. So, less than $100 tells me you are in a bungalow in Miami with your own gas well.

MaxMercy

SlamDunk said:

So, less than $100 tells me you are in a bungalow in Miami with your own gas well.

Or a bypassed meter..

At my commercial building, Connecticut Loot and Plunder charges me about $800 per year just for "carrying charges", even if I use zero gas.

mattmia2

Or the meter is as old as the conversion burner and underreads significantly. Or the regulator is running much higher pressure than the meter is calibrated for.

ChrisJ

mattmia2 said:

Or the meter is as old as the conversion burner and underreads significantly. Or the regulator is running much higher pressure than the meter is calibrated for.

The meter measures volume so unless it's really really high pressure ...... And I don't see how the gas company would miss that...

Ironman

I wouldn't wanna spend one night in the house with that boiler.

Solid_Fuel_Man

@MaxMercy lol! Connecticut Loot and Plunder 

mattmia2

It looks like there is a hole in the firebox next to the door

Ironman

mattmia2 said:

It looks like there is a hole in the firebox next to the door

You're right.

That thing should be red tagged and shutdown.