Is it normal for there to be enough volts in your plumbing to ignite steel wool?

[Bruno]

Because there is in mine.

We got a used washer and dryer last week, but I noticed a burning plastic smell whenever it was running. Sniffing around, I found a leaky joint in the pipe going into the cold side of the hot water heater. Being aware of this, I watched it as I started the dryer and saw a puff of smoke, and what looked like an electrical arc coming from underneath the white translucent plastic around the valve.

Apparently, the current was enough to burn through the Teflon tape, or some other piece of plastic that breaks the continuity of the metal pipe and cause the leak. I've temporarily bridged the joint with a piece of copper wire to keep it from damaging the joint any more, and we now have a house rule against running the dryer while someone is in the shower.

Just now, I broke the link on one side of the copper wire, and stuck a piece of steel wool in between the wire and the pipe. This was the result:

https://www.youtube.com/watch?v=88xlL-8eMAM&feature=plcp

Also, with the voltmeter I get max voltage of 8-9 volts accross the valve.

The dryer is on a separate breaker from the water heater, and I get the same result even when the breaker for the water heater is shut off.

I shut off both breakers, and tested the resistance between the neutral of the dryer outlet and the case of the water heater and found a fraction of an ohm between them. I suspect that something is up with the connection to neutral in the dryer outlet, or that it is simply grounded directly to the plumbing, which would be stupid, since ground isn't meant to carry load current like neutral is.

I also suspect that some section of the plumbing under the house is PVC, rather than copper, which is preventing a good ground.


SCIENCE!

[ñͤͣ̄ͦ̌̑͗͊͛͂͗ ̸̨̨̣̺̼̣̜͙͈͕̮̊̈́̈͂͛̽͊ͭ̓͆ͅé ̰̓̓́ͯ́́͞]

One of your neighbors is an android that takes electromotive dumps.

Mystery solved.

[Bruno]

This house is actually a duplex, and the water heater is right next to the wall between the, um... plexes, I guess.

I imagine that the neighbor's water heater is probably just on the other side of the wall, and I have wondered if there is any connection between plexes. We do have separate meters.

[Mesozoic Mister Nigel]

I'm betting you're right about the house, or at least one device in the house, being grounded directly to the plumbing, and about your suspicion that there's PVC somewhere in your plumbing. Call your landlord ASAP. Sound panicked.

[Phox]

Wow. Yeah, definitely call your landlord or what have you. That looks and sounds pretty damn dangerous.

[Luna]

Call, preferably before somebody flips a light switch while you're sitting on the john.   

[Bruno]

This is all excellent advice, I'm sure, but the mad scientist in me wants to wait until I can get my hands on a clamp meter so I can find out how much current is flowing through that pipe.

Whatever is wrong has been that way since we moved in a year ago. The only change is the dryer, which I am keeping shut off at the breaker when not in use, and we both know not to start the dryer while someone is in the shower.

[Mesozoic Mister Nigel]

I don't know if I actually have to comment on the fact that there is at least one other tenant in your building who may not be playing by the same rules.

[Phox]

This is all excellent advice, I'm sure, but the mad scientist in me wants to wait until I can get my hands on a clamp meter so I can find out how much current is flowing through that pipe.

Whatever is wrong has been that way since we moved in a year ago. The only change is the dryer, which I am keeping shut off at the breaker when not in use, and we both know not to start the dryer while someone is in the shower.

Are there separate water heaters? If so, you might want to ask your neighbor if you (or they) can see if theirs has the same problem. Either way, you should at least make them aware of the situation.

[Bruno]

That's a good point, Nigel. I don't know how shit's connected down there.

Phox, the water heaters are separate, but who knows how or where the grounds are connected.

[Phox]

That's a good point, Nigel. I don't know how shit's connected down there.

Phox, the water heaters are separate, but who knows how or where the grounds are connected.

Righto. All the more reason to enlist your neighbor's cooperation. (besides more angry letters and phone calls being made, of course)

[Bruno]

Our landlord is a pretty nice guy, actually. Part of the reason I'm being all "scientific" about it is to try and help him fix the problem.

[Suu]

This is the second case of apparent ungrounded plumbing I've read this week.

The other involves getting shocked at the kitchen sink WHILE WATER WAS RUNNING. They thought it was "static." 

SCIENCE is all well and good, and I appreciate that you're documenting the results, but FOR FUCK'S SAKE, seriously get that fixed before you or your neighbor or someone else gets pretty hurt.

[Mesozoic Mister Nigel]

Our landlord is a pretty nice guy, actually. Part of the reason I'm being all "scientific" about it is to try and help him fix the problem.

The "scientific" method would be to get a fucking electrician in there before it burns down and somebody dies. FFS. Stop being a fucking idiot.

[Mesozoic Mister Nigel]

Also, if the place catches fire and it comes out that you knew about it and didn't report it, you could be held liable. If the landlord is a "pretty nice guy" stop fucking around with his investment. I had an ungrounded circuit in my house and it cost sixty bucks to fix it, which is a fuckton less than my insurance deductible if the place had caught on fire. Or funeral arrangements for my kids.