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Weil McLain 97+ boiler: PP or CPVC?

Matt Wynne
Matt Wynne Member Posts: 8

I'm installing the above system in my house. I would like to vent with polypropylene, but the manual states that 1st pipe connection to the boiler must be CPVC, which has a lower max temp.

I called them asking about this and they said it was because the engineers tested the system with CPVC.

Since I would like to run this rig with a return temp that would approach the max temp for CPVC, I would feel better venting it with PP. So, PP makes better sense and is safer, but I would risk voiding of warranty.

Any thoughts?


  • RobG
    RobG Member Posts: 1,850
    Use PP. It's a better product. Manufacturers allow following the vent manufacturers guidelines. Just call the PP manufacturer to ensure it's OK with them.