Imploding hot water heater?

[Eric G.]

I've got some idiot at work telling me that his hot water heater imploded. I'm telling him that is impossible, but I want to make sure I'm not the idiot. Technically, I guess anything is possible, but being on city water, wouldn't every fire hydrant in the neighborhood have to be running at the same time to cause enough of a vacuum for implosion on a vessel that is supposed to be able to withstand 300PSI of pressure? And that would be only after everything else between the main and the HWH survived the vacuum first.

Anyone ever heard of this happening?

I'm 99% sure that it exploded on him, but he was lucky. From what he told me, his limit switch has failed, and his T&P is 15 years old (installed with the HWH).

Anyway, I haven't had a chance to look at it yet myself, so there is a lot of specualtion here, but I just want to know if anyone ever heard of a HWH imploding.

Eric

[drd]

well ....

if the vessel were full of steam, and it were suddenly cooled, the steam would condense with a large change of volume and possibly create enough vacuum to implode the vessel ...

this used to be a standard physics experiment at school - get a large screw top can - remove the lid and boil a small volume of water in the can. when it is boiling nicely put the lid on a run the can under cold water ... it folds like a house of cards! this,

is the closest I can find on the interweb ...

[Bob Wheatley]

All the scientific hypothesizing bullshit aside.... Bullshit! :>) If his limit switch fails then his thermostat also had to fail, his T&P had to fail, and he has to have a check valve on his incoming domestic supply. And what does those conditions lead to? Excessive pressure. Not vacuum. He's pullin' your chain.

Bob Wheatley

[drd]

IANAP ... but IAAS

I feel I have to support the hypothetical scientific viewpoint here ...

Is there not a scenario where the cold water feed fails for some other disconnected reason (dodgy check valve perhaps?) - the boiler continues to heat the little water there is, filling the boiler with steam and hot water vapour - the cold water feed is then reinstated for some other disconnected reason, resulting in rapid cooling of the boiler vessel - the pressure relief valve would snap shut and a pressure drop would be seen. I couldn't comment on whether this would then be sufficient to collapse the boiler vessel but I have done the can experiment and can vouch for the force of atmospheric pressure!

Most likely is that your mate is 'confused' ...

What's the US plumbing view on Evolution vs Creationism? Are those fossils really only 7000 years old or are they pulling our chain????

[Eric G.]

"Bob Wheatley" wrote in news: [e-mail]:

Agreed Bob, but I had to ask. Incidentally he DOES NOT have a check valve on his service, which just may be what saved his ass.

Thanks for your input.

Eric

[Bob Wheatley]

Okay, but... This isn't a controlled experiment. It's an alleged incident occurring in real world conditions on a real world plumbing system. The conditions you describe DO NOT exist without purposely designing an unsafe plumbing system. Which of course is the direct opposite intent of modern systems. (excluding Europe of course!) :>)

While I believe plumbing has evolved, each system is most definitely created.:>)

Bob Wheatley

[kennybs]

I fully agree with Bob here, the guys pulling your chain. Unless you can explain how 14.7lbs of external pressure could crush a water heater, and that would be in a perfect vacuum at sea level.

kenny b

[drd]

aha - you've seen British plumbing! Spanish is worse though ... and dont get me started on the French - sacre bleu!

LOL

8-)

[Eric G.]

Finally got to look last night. It exploded right along the seam of the tank. Don't know where he pulled the implosion thing from, but I'm pretty sure it was outta his ass.

This was probably one of the worst looking piece of shit tanks I have ever seen. I really couldn't believe he made it this long without something else going on, but then he told me that he had been manually running the tank for the last 2 years or so, getting the water up to about 180F and then shutting it off. So I guess the thermostat and limit switch have been bad for quite some time. He also told me that the T&P blew on him about 6 months ago.

I took the time to show him the exploding HWH heater video that I found on Youtube, and I don't think he'll be quite as stupid in the future.

And the guy is a friggin mechanic for God sake. Not like the average homeowner.

Eric

[Alan Scobie]

replying to Eric G., Alan Scobie wrote: I am a plumber of 45years and I have had to replace 2 hot water cyllinders that imploded

[Ninja]

replying to Alan Scobie, Ninja wrote: This is a little off of the subject but I wanted to ask you guys who are experienced plumbers. Today I needed to change a angle stop under my kitchen sink on the hot water side. I told my little brother to shut off the valve thinking he would shut off the main supply valve to the house. He shut off the ball valve on the hot water heater without me knowing about it. I went to drain the hot water from the line and I heard the tank pop and make some subtle crackling noises. I immediately turned the hot water off. I realized he turned off the wrong valve. I only drained maybe a 1/4 gallon of water out. Do you think the heater tank has been damaged from this ? Thank you for any help with this.

[Jon Williams]

specualtion here, but Implosion can happen with water heaters that are exposed to cold weather! Everything sucks in. You can usually tell by galvanized nipples. They will be slanted sideways!

[Julia Milstead]

replying to Eric G., Julia Milstead wrote: Our hot water tank just imploded. I never heard of it before, but trust me - it IMploded. The parts on the top of the tank were sucked right into the tank and the pipes sucked into it. The cause is not certain, but the water mains in our neighborhood were being flushed that day which may have caused a vacuum in our system. There is a pressure valve that is supposed to prevent that from happening, but apparently it failed because of some corrosion.

[Bob]

replying to Eric G., Bob wrote: If a hot water tank fills with steam, then even a tiny amount of cold water getting in is likely to cause a catastrophic implosion. This is common with immersion heater tanks if the thermostat fails. See "imploding can experiment" on Google.