New boiler blasted concrete underneath it. Any ideas why?

ChrisJ

Bob Bona said:

That's pretty bad Gordy. Except for the tube with the t-couple. Someone manages to flip that one, wow. Still going to check mine

Maybe it's just me, but if someone can't pay enough attention to the orientation of a burner tube I really don't want them working on anything in my house including the bath mat.

Like many have said over and over again you can only make things so "safe".

Gordy

I agree whole heartedly Chris.

All though if the concrete popped once it can do it again even in the same area.

He'll like I said I don't even know how the flame would light off or act in an upside down configuration.

ChrisJ

Gordy said:

I agree whole heartedly Chris.

All though if the concrete popped once it can do it again even in the same area.

He'll like I said I don't even know how the flame would light off or act in an upside down configuration.

Are you saying you don't like the way the burner tubes can be flipped, or you don't like how the hot block sits right on the floor?

As far as I know, the two loud pops I had in 2011 were from wet concrete + the hot block, not the burner setup.

As far as lighting off, I doubt the pilot would work but let's assume most tubes were right, but one or two were wrong? Would they light, or would they put a ton of raw fuel along the floor that would suddenly go off with a bang?

Fred

As far as lighting off, I doubt the pilot would work but let's assume most tubes were right, but one or two were wrong? Would they light, or would they put a ton of raw fuel along the floor that would suddenly go off with a bang?
In a confined space like that with flames running across that area, I wouldn't think there would be time for an accumulation of raw fuel??? I would expect flames from the next burner tube over would lap over to that raw fuel as it was being expelled from the upside down tube ???

ChrisJ

I don't know.
What I do know is I'm not willing to find out.


We still don't know if this was LP or not as well.

Gordy

IF the tubes were assembled wrong that's just an idiot. Hot block conducting to cold concrete..... Why transfer btus to the concrete keep it in the block.

ChrisJ

Gordy said:

IF the tubes were assembled wrong that's just an idiot. Hot block conducting to cold concrete..... Why transfer btus to the concrete keep it in the block.

The only boiler I can think of that doesn't do this is the Burnham IN series. I thought all others had the block sitting directly on the floor or blocks?

Gordy

Okay I retract my statement about tubes fitting perfectly upside down. At least on my WM CGM. There IS a slight bend on the top of the tube on the opposite end of the orfice that will not allow it to fully seat in the rack if turned upside down. But it will sit in the rack a little, but the tube will not point straight down because of the slight bend so the flame would not point straight down more so at a,30 degree angle from down.

It is carelessly possible for an incompetent person to be in a hurry not paying attention, and throw one in wrong, and not notice unless your looking way to the back the variation in Height is less pronounced towards the front.

I do not know about the one in question, but I would think WM would have thought that out thus the bend in the tube would be enough for a competent person to realize something was not fitting right. .......there are,some Darwins out there who would take pliers, and straighten the bend so it could fit though.

Like KC said earlier my brain won't let my hands light it off in that position to see what happens even with an ill fit.

Bob Bona_4

Lol Gordy, bend the dog ears straight. Good one!

Still think even if one tube was flipped, the lock down panel would not be able to fitted right. But, hey, make a new screw hole!

KC_Jones

I just looked at mine and it flipped right over. I was starting to think I was losing my mind. Now I am thinking mine has some kind of defect. Very weird. I believe almost anything.

jonny88

Maybe way of the mark here but had a TT399 pop yesterday.Blew the top cover of hx.Presumably gas valve opened and ignitor failed?TT are coming to assess.Is it possible something like this may have happened,an accumulation of gas and then ignition causing boiler to blow??

Gordy

im waiting to here back from OP??

unclejohn

Believe it or not I have seen a new install with tubes upside down. Was called in by a friend who had his guys install it and the customer called saying the brand new boiler was not working. I think his guys where drunk. The boiler was placed on bricks and was piped with 6" nipples and couplings. Since the boiler was up on bricks no floor damage but I think even if it was on the floor the flame just kinda shot up around the burner. Needless to say two guys where out of work that day.

Homeowner3

I owe y'all a full report--but I am too exhausted right now. Please forgive me?

I just wanted to clarify that I do not think the burners were installed upside down, based on what I saw (and I looked!) prior to start up yesterday. They seemed to all be sitting properly. And they have no discernible damage or discoloration on them now (I looked while the installer was here today). I will try to take a picture of the shape, etc. as well as what they would look like/how they would sit if they had been upside down, just since we are all now curious about this...

It was just a theory that occurred to me (and others on here who were kind enough to "talk" to me) late last night after the Fire Department and everyone else left, as I tried to figure out what on earth could have gotten the boiler so hot as to spald the floor and melt the heat sensor that sits above the burners on the manifold!!! We were simply casting about for an explanation. Based on what I saw with my own two eyes, though, that can't be the cause of the explosion.

So, I still don't know what caused the problem.

As it is unclear that the boiler is safe to turn on, we have a cold house tonight...

I also wanted to clarify one point: the installer I chose is a really good guy. He has patiently and thoughtfully considered and answered 20,000 questions from me. He has called me on Saturdays to discuss the NBP concerns/requests I outlined in emails and go over the cleaning process post-installation. He has watched video clips I found on this site, and read links to posts and articles here. He has a genuine interest in steam and takes pride in his work. (The policeman and fireman who were in my basement--both hung out to look at his install, complimented him, and the fireman asked me where I found him and asked for his contact information. They said they never see an install this nice.) I know y'all see a lot of crazy, absolutely terrible installs. This was not one of those.

I have to go to bed. But I promise that I will update everyone as soon as I know something.

Thanks to all!

Gordy

So if you don't know the installer does not know either? Melted the roll out sensor?

nicholas bonham-carter

Maybe the burner was set up for an alternative fuel, such as LP, and the resulting flames were too high.--NBC

JUGHNE

Has the NG or LPG question been answered? If the house has LPG and boiler is set up for NG then orifices would have been way oversized. I think you would know right away.

unclejohn

We seem to be getting the info in dribbs and drabs. First the vent damper failed now something is melted.

unclejohn

If the damper failed and the burners keep firing there will be a lot of heat, enough to cause the boom and that means the only thing that stopped the gas flow was the boom that took out the pilot safety.

ChrisJ

unclejohn said:

If the damper failed and the burners keep firing there will be a lot of heat, enough to cause the boom and that means the only thing that stopped the gas flow was the boom that took out the pilot safety.

I thought they asked IF the damper failed, could it cause this. I didn't think they actually said it failed shut. Also there's a 99.9% chance if it did fail, the burner couldn't light.

If some how the damper stuck shut and the burner did light, the drafthood setup would provide proper draft to the burner regardless. No excess amount of heat, no boom, not even much of an increase if any in CO. That's a big part of a drafthoods design, to stop downdrafts and a blocked flue condition from effecting burner performance.

JUGHNE

FWIW just a theory/guess idea. The boiler was on for 30-40 minutes. Then perhaps pressure control shut it down, gas valve closes enough to snuff out flame....but not 100%....gas seeps in filling heat exchanger chamber.....damper has closed and the gravity pull of chimney is lost........then steam pressure drops and p-troll goes for ignition. If the right mixture of air/gas was present explosion could occur. (either LP or NG)

IIWM and the boiler is to be reused I would want everything replaced except the block and jacket.

I would expect there to be white hard hats and clipboards on site as company reps; they want to release no info until they are certain of the cause and then maybe not even then.

Gordy

@JUGHNE That's a good theory, but is that enough force to pop the concrete? I would not think so. If so I think there would have been a lot more damage. Something deffinetly caused roll out enough to melt that very sensor. So was the roll out sensor defective in some way to not shut down quick enough?

JUGHNE

A wild shot is that this produced a "Shape Charge".

So we all have a "which came first-the chicken or the egg".
Did the concrete explode wrecking the boiler?
Or did the boiler have an explosion wrecking the concrete?

And how do you explain all of this to your homeowner insurance company?

Fred

And how do you explain all of this to your homeowner insurance company?
That is the easy part. I mean the concrete can't explode, in and off itself. It has to be a direct or indirect result of the boiler. It will probably be more difficult for them to decide if the explosion was the result of a flawed installation, something defective in/on the boiler and where the liability lies.
I'd still love to know what actually happened.

BobC

I can't see how unconfined gas would form a shape charge. It's a shame he didn't take some detailed pictures of the immediate aftermath. There may have been an identifiable pattern.

Bob

Fred

Hatterasguy said:

"Hello Hartford"

"Yes"

"Have an explosion beneath my boiler. I mean, the concrete can't explode, in and of itself. I has to be a direct or indirect result of the boiler"

"Well, sir, of course you are correct. We'll get an adjuster right out there and take care of this immediately".

OR:
Hello Hartford
"Yes"
"My new boiler exploded and did some damage to the concrete floor."
"When was the boiler installed?"
"Yesterday"
"Give me the name and number of the installation company"
"It was ............... and their number is"
"Fax me a copy of the permit, please"
"Ahhhh"

JUGHNE

In my wild speculation the shape charge would have been formed between the boiler sections and gas stacking up as the vent damper would be closed. No high draft from chimney at that time.....I know, call me crazy.

BobC

That could make a good bang but I'm not sure it would be enough to remove the concrete except for those spots the burner tubes impacted.

Without pictures it's all speculation.

Bob

Harvey Ramer

I may as well speculate on possible cause as well.

First of all, I have never run across a melted roll out sensor. Second, I have a really hard time believing the boiler could have created enough heat to bust the concrete.
I mean, I guess it could be possible but I would consider it a slim possibility.

One of the first things I would look for would be oil soaked (or other combustibles) concrete underneath the boiler. Old boiler may have been oil? The new boiler definitely could have ignited it. That would explain both the melted rollout switch and the popped concrete.

Gordy

I'm a little disappointed the OP has not returned with some decipherable information. Some things just don't add up here.

Fred

Gordy said:

I'm a little disappointed the OP has not returned with some decipherable information. Some things just don't add up here.

I agree. I suspect they may be in a quandry with WM not taking any responsibility, probably the installer not wanting to assume responsibility and the HO insurance not wanting to cover any damage/repair because it is a new install. There is always the question of "was a permit acquired for the install?" Here in our county, it is the responsibility of the homeowner to ensure all required permits are acquired.

Gordy

no pics nothing is the op still with out heat ? Is WM performing investigation?

bob_46

how hot? I got involved with a house that had a 500,000 nat. gas atmospheric pin boiler installed on the second floor for snow melt on the roof,gutters and some balconies. House caught on fire. Boiler was sitting on a 4" concrete pad poured on the plywood subfloor. Not a lot of fire damage but a couple mill of smoke and water damage. It was hard to tell exact cause. There was another house next door with same exact set up. We pulled the boiler and the pad the plywood was charred . They were luck that one didn't burn. Even though the air under the boiler doesn't get hot the radiant heat from the burners is enough to start a fire under 4" of concrete. It was the contractors fault the mfg. instructions called for concrete block on it's side under the slab providing an air space.

Gordy

I have seen concrete pop from bond fires with fire pits built with concrete around perimeter.

It takes a lot of direct heat to get concrete popping. Say a weed burner type flame wouldn't do it right away, but a blow torch , and not a propane torch would Pop it pretty quick depending on moisture absorbed.

Im starting to wonder if the concrete was damaged prior, either from removing old boiler, or installing new. The piece of concrete could have been just laying in its pocket until the incident happened, and then Jared it loose.

unclejohn

Chrisj; If the vent damper is installed at the boiler rather then above the draft hood enough heat could build up. But like we are all wondering where are the pictures.

JUGHNE

The Boy Scout Handbook warns not to build your campfire pit with rocks from the river as the result could kill or maim.
A folklore method of sabotage to the enemy campsite was to sneak river rock into their campfire and wait some time for the explosion and then have them at a disadvantage during the chaos that followed.

ChrisJ

unclejohn said:

Chrisj; If the vent damper is installed at the boiler rather then above the draft hood enough heat could build up. But like we are all wondering where are the pictures.

EG series has a built in drafthood.