It can??

[Amanda_931]

[size=18]Critical! [/size]- Under certain conditions, hydrogen may be produced in a hot water
system that has not been used for over 2 weeks. Hydrogen gas is explosive
and can be dangerous if left in the water system. If your hot water has not
been used for over 2 weeks, turn on all hot water faucets and let the water
flow from each faucet simultaneously for several minutes. Do not smoke or
use an open flame during this process.

from the Thor washer dryer manual .pdf file.

http://www.thorappliances.com/installation/9900Manual.pdf

[Amanda_931]

I'd really like to have a washer (with a dryer would be very nice) that was usable here, outdoors, in the winter.

It doesn't sound like this is it.

Their website comparison that tells us how great they are compares apples to oranges--no horizontal axis machines in the mix, for instance.  

http://www.thorappliances.com/thorModels/index.php

[JRR]

I'm guessing that if an element cracked in an electric water heater, you might (if everything was just "so") have enough electrical current to break down the water into gasses.

May be some other metal action going on.  

Never heard of this before.

[John_C]

I think it's a real stretch.  IF the conditions were just right and a small amount of water did break down into hydrogen & oxygen they would be hanging around at the top of the water heater where they would in all likelihood combine and form water.

Does anyone know of a verifiable instance of this happening?

[Amanda_931]

Not me.

All I was running into was electrolyzers--which seem to require DC rather than AC current.

http://www.homepower.com/files/Hp32p42.pdf

Plenty on hydrogen sulfide, though.

And that is flammable.

http://en.wikipedia.org/wiki/Hydrogen_sulfide

Hydrogen sulfide (hydrogen sulphide in British English), H2S, is a colorless, toxic, flammable gas that is responsible for the foul odor of rotten eggs and flatulence. It often results when bacteria break down organic matter in the absence of oxygen, such as in swamps, and sewers (alongside the process of anaerobic digestion). It also occurs in volcanic gases, natural gas and some well waters. This is the odor that is commonly misattributed to elemental sulfur, which is in fact odorless.

Hydrogen sulfide is also known as sulfane, sulfur hydride, sour gas, sulfurated hydrogen, hydrosulfuric acid, sewer gas and stink damp.

There are some interesting bits on the wikipedia page

[John_C]

Wish this had come up last week when my daughter, who is a chemistry major, was home for spring break.   We had a lot of conversations about breaking down water to get hydrogen.   I have a neighbor who wants to be a ground floor investor in hydrogen fuel technology.  There are a lot of hurdles to overcome before it is economically viable.  We never spoke about sulfur compounds, but we don't have any/much sulfur in our water either.

I keep rereading your original post.  I've never seen that kind of admonition anywhere else.  Make me wonder if some liability lawyer read about the one and only suspected such incident and recommended the disclaimer.

[glenn kangiser]

Some water naturally has hydrogen sulfide and or methane  in it and it will burn as it comes out of the well.  I know of a well we worked on and one we drilled with the problem.  The one we drilled would shoot 10 foot flames when lit, but only when pumping.  

Not quite the same problem as they are talking about here, and I have not heard of this happening.