Convert to HW from Steam w/Pex

Tom Giedraitis

In repiping to convert from steam to hot water with Pex, have any of you used the existing steel steam risers as "conduit" to pull 3/8 pex supply & return lines from the basement to the 2nd floor radiator locations?

This seems feasible, but I would think only if I'm staying in 45 degree bends. Can I pull through a 90 and not expect the pipe to kinked or damaged?

Any advice is appreciated.
I'm trying to get to some tough spots so using the old pipe is ideal, but I'm a bit concerned with this "methodology."

Steamhead

Tom, that sounds risky

Not only might the PEX kink when going around a 90, but you don't know how well the old pipe was reamed after cutting. I've seen some pretty sharp edges in old pipe, which would shred PEX in a heartbeat.

Tom Giedraitis

That was my concern. My contractor was proposing to do it this way when I first discussed it with him.
It seems risky to me as well.
Thanks for the feedback.

Steamhead

Why

does he want to convert the system in the first place? We've had people cut their fuel bills by 75% or so just by fixing whatever problems their steam systems had.....

Weezbo

thru 3/4 quest (grey pipe)

i have pulled 1/2" 3/8ths 5/16ths ....however iron pipe is a little different animal.... my thought would be to lose the fittings in the black iron, find the 90 chop it out use the 2" as a chase.use the space to make up 1/2" fitting 90 ,making straight runns to it.... if you are doing the work with someone else who knows how ta doit and either feed it correctly or make the pull correctly and you dont have more than one fitting to roll thru i think it will work quick and easy.