"Jeff Wisnia" wrote in message
...
miamicuse wrote:

The union that connects the copper pipe and the nipple that comes out of
the
heater for the hot water is corroded. I got a plumber here to replace
it.
He got here, turned off water, turned off electric, unscrewed the union
and
wow, I saw some scary stuff. Inside the union. It's black, looks like a
pile of tar. I could not believe it. I was wondering if it could be
sewage
back flowing into the water heater, totally black yucky stuff. He looked
at
it and told me it's normal, just "stuff" from minerals in the water
getting
heated and turn into this. Is this normal? It looks scary to me, that
stuff is in the water I take shower with? Could it be sewage blackflow?

MC



While you didn't say it, I bet the nipples (and maybe the union) were
steel.

What you see there is soft corrosion products (rust) which cngegates there
because of galvanic corrosion from to the juncture of dissimilar metals.
If you run copper, including a copper union, all the way to the tank you
won't get that stuff there.

The page from Rheem explains it:

http://www.rheem.com/includes/resour...ryPDF/1221.pdf

Jeff

--
Jeffry Wisnia

I've had this problem over the years -- corrosion at or next to the pipe
nipples. With steel nipples and copper piping the nipple corrodes like mad
in our softened hard water. With copper nipples, corrosion occurs on the
tank next to the nipple. Recently, plastic lined steel nipples have become
available for this connection. I got mine at Lowe's after reading about
them somewhere. I'm very hopeful that this will solve a pesky problem.

SJF