Frozen Steam Boiler

EBEBRATT-Ed

Our "service manager" sent a tech on a no heat call. This is a semi abandoned building where they have all the plumbing drained but are keeping the heat on low. So he gets there and has ice in the gage glass and frozen in the LWCO nothing coming out of the boiler drain.

Apparently the maintenance people check the building once a week. Apparently they should be checking it once a day if the temps are below 32deg IMHO

He's a young kid but pretty smart. Calls the service manage who tells him to light it off and thaw it out. The kid says he doesn't think that's a good idea, the sm insists, the kid says ok I'll do it but I am putting your name on the paperwork. (told u the kid was smart) so the sm backs down and tells him to "call the old man" and see what he thinks

So my phone was in the truck charging so I didn't get the message until an hour later by which time he had left the job without starting it up.

Told him NO Dont start it, you did the right thing. Get some temp heaters and warm the boiler room till it thaws which he said the maintenance staff was already doing that.

Well, the boiler is probably toast but IMHO the toast would have been burnt for sure if he lit it off.

Jamie Hall

Oh dear. But you do have one smart assistant there!

j a_2

Pretty stupid all around, except for the young man who had brains enough to not lite it off. Service manager is way over his head, Burger King might would be a better place for him....

mikeg2015

Just curious, what would happen? I assume it would start flashing steam as soon as a film of water formed between casting and I’ve block. Would he almost like dry firing it I’d guess.

If desperate I suppose you could fire it in 30 second bursts. Then wait 3-5 minutes. But might thermally shock it even then.

EBEBRATT-Ed

@mikeg2015 . I think your right

I was thinking the same thing. I think the thermal shock would kill it for sure (if it isn't already toast)

Aside from the thermal shock I wonder about the ice's ability to transfer heat away from the sections as water would. Don't think it would.

It's probably toast anyhow, maybe a slim chance it's ok. Why take a chance heat it up slowly and see what happens?

But even with 32 deg water in it your approach with intermittent firing is a good idea

Jamie Hall

The 32 degree water would help -- a lot. But your thought, @EBEBRATT-Ed , is also right on -- the conductivity of the ice is horrible, so you'd need to fire it in brief bursts. Have you thought (assuming you need to get the thing thawed!) of taking the burner off or swinging it aside, and directing the hot air from a construction type salamander heater in there? Much lower temperature, so much less thermal shock...

SeymourCates

The thermal conductivity of ice is roughly 4X the thermal conductivity of water (2.18 vs. .58 w/m K°) so that won't explain the problem of firing it with ice present.

The issue is the lack of water. Once the ice melts way from the CI, the CI will have nothing to take the heat away until sufficient ice melts and fills the space with water.

If you simply fill the frozen boiler with water above the level of the ice, you can fire at will.

hvacfreak2

I would also consider that the mechanical lwco is suspect as well ( op mentions no fluid when the drain was opened ). The manufacturer only recommends these things stay in service for 5 years ( in the case of the MM67 ) , so I'd imagine a freeze has to come with a higher tax regarding service life.

Gordy

Hang on to that kid!

I think warming to room temp externally is the only sure way to know if it were salvageable.

Firing with the burner to thaw would create all kinds of stress to the cast

ChrisJ

If it was mine,and not a customers I'd probably fire it for a few minutes and shut it down for a few until it thawed. Something like on for 5 off for 10-15 minutes.

I don't know what the results would be but I'd expect a new lwco at a minimum.

JUGHNE

Urban legend is that one would build a fire under their Model T to thaw out the engine. (Apparently they never had oil/gas leaks).

Gordy

^hard on the paint......

JUGHNE

"Any color you want as long as it is black"

Jamie Hall

JUGHNE said:

Urban legend is that one would build a fire under their Model T to thaw out the engine. (Apparently they never had oil/gas leaks).

I haven't quite done that -- but I have used one of those lovely kerosene fueled construction heater dragon things to thaw a tractor enough to get it started. Oil leaks just burn off...

mikeg2015

maybe it would work then. Plus as you flash off water you may draw a vacuum and maybe even start to sublimate the ice in small pockets.

I’m getting ready to test this. I’m on vacation and my boiler crapped out right after I left. Service guy is checking it out today. I was talking my wife through some troubleshooting. But I think it’s a loose wire or transformer is bad. Has water. Not flooded. Safeties all made. Has a call for heat. But ignition sequence isn’t starting.

House is down to 53f after 25 hours since boiler last ran.

My 5 tons of heat pump capacity is the little engine that couldn’t. Itsdoing all it can. Outside temps is 3f and falling right now. My math says it can keep the house above 40f. But don’t know if they will run with return temps under 45-50f.

EBEBRATT-Ed

If I get sent there I am not doing anything until I see water in the gage glass. Let's face it, unless extreamly lucky this thing is probably toast. As soon as it starts to thaw there will be water on the floor.

The maintenance dept are the real idiots. You can't check a vacant building 1 a week in this kind of weather. I would be happy with 1/day

just cracked me up that he told the kid to fire it

ChrisJ

EBEBRATT-Ed said:

If I get sent there I am not doing anything until I see water in the gage glass. Let's face it, unless extreamly lucky this thing is probably toast. As soon as it starts to thaw there will be water on the floor.

The maintenance dept are the real idiots. You can't check a vacant building 1 a week in this kind of weather. I would be happy with 1/day

just cracked me up that he told the kid to fire it

I don't know if it was good advice or not.

But I don't like the fact he wasn't willing to put his name on it. That's very uncool. You're willing to tell someone to do something that you may not do yourself? Pfft.

Paul48

There's lots of room for expansion in there. It may surprise you.