Hot Water to Steam

John David Layton

I have a house that appears to have been originnaly a steam system that was converted to HW (two pipe). I am contemplating reverting to steam. However the risers are 1 to 1 1/4". Home is three stories, seems like most radiators are on home runs to horizontal 4" main in basement. Can someone advise if risers are appropriately sized?

Steamhead

That would depend

on the radiation load the risers must handle. If the rads have not been changed, you should be OK.

But that may also have been a gravity hot-water system. If the mains and risers pitch up from the boiler, and they're the same size supply and return, it was a gravity HW system. If the return is smaller than the supply (applies to mains and risers) it was steam.