Older Weil McLain boiler; fire box corrosion

Hello again. Summer is upon us, and I got luckier than I deserved. No more mishaps with the boiler, and my jerry-rigged burner got us through.

Thanks again to those who gave their opinion and answered my questions.

For my edification — and your entertainment — today I started tearing into the boiler to see if I could learn anything. I still need to find a competent contractor, which is not going to be easy in this area. So whatever I can learn is a bonus.

First up though: Someone tell me there CAN'T be asbestos in this thing… right??? It was banned in 1989, and my boiler has a 1992 serial number according to the manufacturer.

This is what the insulation looks like:

and like this:

I'll post more pictures later. But I hope I just didn't do something really stoopid.

-Matt

I found a youtube video titled "Near-Boiler Piping in Steam Heating Systems" by a Dan Holloman, who's written a bunch of books on the subject; his name comes up in the forums a bit. Which one(s) do you recommend I buy?

The video is excellent, at least to my layman's mind. I can alreaydy see a bunch of problems with my installations, starting with the use of copper, and the way the pipes directly out of the boiler set the two streams of steam up for a collision where they come together.

Apparently it should look like so — the pointer is from the explanation how you get water problems at that location if the steam went upwards there — but mine looks like the picture below.

To say nothing of the lack of the big valve that can be shut to use water pressure to blow the mud out, which I obviously can't do with my setup.
At least I got the, ah, "insulation" removed around the boiler.

Thanks, everyone.

I appreciate the input. I will try to not dribble out information over lots of posts.
So without trying to be complete, here are some thoughts.

@Erin Holohan Haskell: Thanks for the welcome. The 'revisited' book arrived yesterday and I have begun my education. So far it's making a lot of sense. Grasping the principles is easy; grasping the practical implications will be a bear. Steam speed, heat transfer, effects of pressure — these are all far outside one's usual experience, so it's going to be difficult to develop a quantitative feel for anything.

@AdmiralYoda, @KC_Jones: I'm used to doing my own work. Plumbing, electrical, the occasional car repair or a new water heater… so far so good. The number one rule is not to get cocky and to be realistic about risk, and be realistic about what I know and do not know. I have not made up my mind at all how far I want to take this, but I have a little time to decide, and whatever I can learn is all to the good.

@EdTheHeaterMan
» the Copper risers are a sign of incompetence on the part of the previous installer. Quite possibly the reason for the boiler leaking that caused the problem to begin with. If youdon't install swing joints so the pipes can give a little during expansion when it heats up and contraction when it cools down, something else has to give. The gaskets between the sections are probably leaking steam and causing that burner box to rot away.

That went right over my head when you wrote it back in January. Having read up about near-boiler piping, it now makes sense and I'm sure you are correct.

I will post again when I have something to report or to ask.

Thanks again to all who responded. Social media have caused a lot of problems, but forums like these, where knowledgeable folk are generously helping others, make it worth while. I do appreciate the support.

-Matt

@BobC

EDIT: thanks for the ComfortCalc link. Those diagrams are really clear.

» That is a colliding header where the system steam takeoff is between the two boiler outlets,

That's what I wondered after I watched a Youtube video on Near-Boiler Piping in Steam Heating Systems
from, you guessed it, the HeatingHelp channel.

While we're at it, there isn't a Hartford loop either.

And the front (South) side of the house is fed from the top of the boiler, as I would expect.. while the rear is plumbed into the condensate return. In other words, it looks to me like the steam has to travel as sketched below…


*********** I'm leaving this image here but it's wrong. See the next post ************** 25 June 2024 -Matt

I took a bunch of pictures of the boiler structure with all the covers and ducting removed. The fire box is a mess, and it looks to me like there was indeed a steam leak to cause the corrosion, but I don't see it. I would expect galvanic corrosion where the copper is piped in, but I don't see that either.

I'll sift through the picture and post some later for amusement's sake. Next time I have a problem, I'd like to catch it early, so I really want to learn what I can from the wreck. Speaking of wreck — fire box as seen from the rear of the boiler (W), and a top rear view. I don't know if the sealing material was meant to fix a leak or if that's how the segments were put together originally.

-Matt

I finally made some progress on the boiler teardown.

As @JakeCK put it:
» I can not express how much I want the next picture you post showing us nothing but the stains on the concrete from where this one stood.

I tried the gentle method of unscrewing things, but that only got me so far.
The threaded rods that tie the sections together actually unscrewed quite easily.

But I cut the water supply line and used my biggest wrench to unscrew the blowout spigot; no dice. I'll either have to use a torch, or just cut it. I'm assuming cutting is the best way?

Before I get the Sawzall out: What should I measure, preserve, photograph to help the installer?

Should I just take a few more pictures and then remove all the copper back to the threads in the steel piping?

I'd be grateful for any advice.
-Matt

Thanks for the feedback, everyone.
I'll answer @JakeCK, @ChrisJ, and @Steamhead in order.

» But please cap off that gas line.

That should have been obvious but wasn't. I took care of it last night, thanks.

» Did you find any actual spots on the block that were leaking?

I did not, and it's bugging me. It would seem that there has to be a leak somewhere, due to the corrosion in the fire box. But it has to be a steam leak, not a water leak, since there is never any water on the ground. And I figured I'd be able to see it, but so far, nothing. I expect I'll get the sections apart with a hammer and a chisel and maybe a crow bar, maybe something will show up. This may not be my last steam leak, and I'd like to know how to spot them.

» How long is the main...

I measure 79 ft of horizontal pipe in a square "loop" under the basement ceiling. Give or take a couple feet.

There is one place where the rear of the house is bumped out and a horizontal line is Tee'd off the main, that's another 10 ft before it goes vertical.

» ..and what pipe size?

The steam enters through iron pipe, 2-7/8 inch outer diameter.

By the time it comes out of the asbestos and becomes the condensate return, it's 2-3/8 OD, and I can't tell where the reduction is made.

I only removed the insulation near the boiler, as instructed by a member here, so it's not easy to see. Someone did a thorough job on the insulation.

» you'll need to install some serious venting on the end of that main.

There is a vent on the end of that line, but it was hidden in the earlier pictures.
Here's what it looked like with the insulation still on, not a great shot:

Thanks again,
-Matt

My first concern with this setup was to get through the winter, which worked out, mostly due to luck.

Now I need new equipment, and I'm not looking to cut corners or to squeeze a few more years out of this old thing. I don't want to go through this again.

For my wife and me, it's not about a low price. Quality comes first. Value, too, we're not made from money.. but cheap is no good if it's "cheap." We can afford a new boiler.

We cannot afford shoddy work.

I now have three leads on local installers, but no real recommendations. It's hearsay and google searches. One thing I can do is show people what I've got, and anyone who doesn't say "OMG the near-boiler piping is wrong" is disqualified. After all, that was everyone's first reaction here.

And after reading a few chapters of the 'Lost art...revisited' book, I now know what they meant.

BTW I just saw the Mikey Pipes youtube clip of the Pyrex-glass-piped McLain boiler. THAT was interesting.

-Matt