Black iron vs copper with brass couplings-pros and cons

I know this has been discussed on the message board, but I can't find the thread.

Piping from steam boiler to a radiator and from a second radiator to the boiler have to be replaced. Project manager wants to repipe using copper with brass couplings to attach to existing black iron.

Anyone with expertise willing to weigh in?

Thanks in advance!

David

We had new work done on radiators and they used copper. i am not a plumber but here is my experience.

Problem with copper is that the solder at the fittings can crack and then leaks. If you do a quick google on the topic you will find that copper is to code in many places, and when properly done it should be fine.

Somehow though, there are a ton of posts about how the heat expansion and contraction often results in the joints leaking. This is the case with ours where we can see it, assuming its also leaking inside the wall. Its not much water so i havent done anything about it.

Why not just use steel? I'm assuming its the added time to cut and thread.