Ray wrote:
Recently we installed in our six-unit apartment building a new furnace. The
installer was a reputable local company. The old header pipes -- those
6-inch pipes that come directly out of the boiler -- were replaced with new
copper pipes.

A local guy who is something of a busibody and claims to be an expert on all
things says this was a mistake. He said the copper pipes will begin leaking
steam within 2 years and will have to be replaced with steel.

It makes no sense to me that a company with a good reputation would install
a furnace that would fail in 2 years.

Still, I'm uneasy enough to ask if there's any remote validity to the
busibody's prediction. I guess the question is whether the industry standard
is copper or steel.

Any comments welcome.

I'm assuming you had a steam or hot water boiler. A furnace usually is
a hot air unit.
If the new unit is steam, it's suppose to be all black steel pipe
leaving the boiler. Copper pipes are not meant for steam.
If however the new unit you installed is a hot -water baseboard sytem,
then copper is the standard.