Hot water heat question

Originally Posted By: wdecker
This post was automatically imported from our archived forum.

Inspected a house yesterday. Old (112 years) and it had circulating hot water heat and cast iron radiators.

Seems that someone (previous owner) had the boiler changes and ran copper hot water pipe halfway up, replacing the old black pipe. Where the two meet, isn't there a problem with galvanic corrostion, or that only happen with galvanized.

In other words, the newer copper piping is dirdctly screded into unions with the old black pipe, no di-electric.


Will Decker
Decker Home Services
Skokie, IL 60076

Originally Posted By: Jay Moge
This post was automatically imported from our archived forum.

seems like there is the potential for galvanic or “dissimilar” metal curosion, however i believe that iron is more currosive than copper, so the copper would effectively draw currosion away from the iron. i’d be more concerned with the copper being properly rated to handle the steam pressur. forced hot water radiators run water no hotter than 210*. and since water boiles at 212+ and steam radiators run water at about 220-230*, it seems a little suspect. sorry if i confused you (or me) even more, but that is what i thought of first. at any rate the copper (if properly rated) should be o.k. becouse it goes along with the “equal to or better than…” theory. icon_cool.gif