Black flaking copper!

[Glennhvac]

I was at a client today to check his heating for fall and took a look at the water heater I replaced about a year ago. Both the hot and cold water copper lines that I had redone were already black. I began looking around and the copper lines to a/c unit are black. The cold water lines are not only black but they are flaking this stuff that kind of looks like graphite when you take some off and rub it between your fingers. The same with new water lines to humidifiers I ran a couple years ago.

The home is too old for the chinese drywall fiasco but that does not mean it is not something similar going on. It's BAD! FWIW the 40' of 1/2 bare copper in his garage going to an outside faucet only has the typical discoloration old penny look that you would expect after 40 plus years. I'm pretty sure I remember the blackened copper from last time I was there but I'm sure I would have noticed that massive flaking issue.

The bright copper is part of the water htr return loop.

Well water with softener and iron removal, no cats, no strange smells, 90 plus PVC vented furnace, tank is not spilling...

Can't tell from this bad photo but that black copper is covered with flakes.


So?
Thanks

 

[FullySprinklered]

Are they storing swimming pool chemicals in the vicinity?

 

[Sponsor]

 

[Glennhvac]

Nope. No pool stuff or any chemicals besides the cleaning type things you would see in any home. Something is going on in the house though. The cold water has flaking but the other is discolored only. Yet the cold in the garage that goes to a faucet is perfectly fine.

 

[Glennhvac]

Odd no one else has seen this but I'm not sure how many of the trades guys check this part of the forum. I just thought it might be the best spot to post.

 

[Dj2]

I guess you posted in the right place...except that nobody has an answer.

We can start a 21 question game.

Was the pipe intensely heated at any time?

When was that coupling installed?

Any chemicals dropped on the pipe recently?

 

[Glennhvac]

Heated no. ALL the copper is black. Cold lines are flaking.
Coupling probably years ago.
No chemicals.
It has to be something in the house. The copper in the attached garage looks like any other decades old copper.

 

[Jadziedzic]

Any chance the house might have been fumigated sometime in the past?

 

[Plumber69]

Is the electrical ground connected to the water line. If so check for power on the ground connection to the water line

 

[Bgard]

I have seen copper do that when in a area with high sulfur content water the sulfur gas is condensed on the sweating cold water lines and causes them to corrode.

 

[FullySprinklered]

Indiana ain't that far from Illinois.

 

[Glennhvac]

Is the electrical ground connected to the water line. If so check for power on the ground connection to the water line

Yes I was starting to wonder about electric and he has a generator system that might be fairly new.

 

[Dj2]

Are any of the affected pipes leaking?

I would replace the sections that flake the most. Check the inside at the same time.

 

[Glennhvac]

Are any of the affected pipes leaking?

I would replace the sections that flake the most. Check the inside at the same time.

No leaking and no external pitting or corrosion. I wish I would have traced that copper in the garage back to see if there was a splice using plastic someplace. That would have been another clue about it having something to do with electric grounding.