Should I replace old radiator feeds?

Javelin

Heating Pros,

We're in the middle of a multi-year restoration of our old 1911 mess of a house. Things are going pretty well, albeit slowly. One question I have... While I've put in a new boiler (with quit a bit of help from you very nice people of this forum), all of the piping is the original iron pipe from the old gravity system. A big part of me thinks that if it isn't broke, don't worry about it, but should I be taking this opportunity to replace the old iron pipe with a more modern PEX or other solution?

I'm currently on the 2nd floor with access to the 2nd floor radiators as well as the 3rd floor radiators from below. Is this something to consider? Or is it opening a can or worms? Do these old 100 year old pipes go bad? Or will I get another 10 years from them?

Any thoughts? Seems like a huge project unless there is a need, but before I seal walls/ceilings back up, figured I'd ask all your input. Do you pros see these old pipes failing?

Thanks in advance for this and all the other help over the years! (and those to come)

Best,

Jay

PS - I did see one pipe that seems like it was already replaced from iron to copper.. Not sure why.. The house had been pretty much abandoned years before we bought it, so maybe it was due to freeze damage?

Jamie Hall

The replacement to copper might have been freeze damage. Since this was originally a gravity system, the odds are that those pipes are much bigger than they need to be for a pumped system -- so the corrosion inside, which is almost certainly there, shouldn't be much of a factor.

What I would do, though, before you close things up, is run the system pressure up to the rating on the pressure relief valve -- probably 30 psi -- and hold it there for a day. It shouldn't drop much. If it does, you may have a weep or leak somewhere, and now would be the time to find it and fix it. Don't forget to run it back down to where it belongs when you are done!