Steel Pipe Hot Water System

[David Smith]

What is the life expectancy of steel pipe in a hot water heating system[?]

[kurt]

I routinely see systems >100 years old that still work fine. You did say steel; did you mean iron? The systems I see are all iron pipe.

Supposedly, (this may be part urban legend) there was some substandard pipe mfg. post WWII that can have problems if was retrofit in for repairs. I am not aware of any way to identify this pipe, if it in fact exists.

When I do find defects, it is most often @ the riser nipples, or in the wet returns @ the boiler. I think that turbulence @ the thread joint collects crud @ the nipples, & the returns get crudded up w/ sediments that ultimately "rot" the pipe.

FTR, I look @ about 250 hot water systems annually in Chicago, & they are all >75 years old.