Welcome! Here are the website rules, as well as some tips for using this forum.
Need to contact us? Visit https://heatinghelp.com/contact-us/.
Click here to Find a Contractor in your area.
If our community has helped you, please consider making a contribution to support this website. Thanks!

Backflow preventer - lead free?

Options
Blend9684
Blend9684 Member Posts: 16
in Gas Heating

I've seen it both ways online - is the backflow preventer prior to the boiler feed supposed to be lead-free?

Comments

  • hot_rod
    hot_rod Member Posts: 26,720
    https://forum.heatinghelp.com/discussion/203266/backflow-preventer-lead-free

    BFD before the fill valve.

    Excellent question and one even the folks that wrote the low lead standard cannot explain, regarding boiler fill valved needing to be LL.

    In theory once water crosses a BFD that is the vented type, there is know way it could back into supply. So does any BFD need to be LL?

    One could argue that if both checks failed, and someone plugged the vent port a backflow condition is possible.

    Same question regarding boiler feed valves. We still see fill valves installed without BFD protection, so it is possible for that backflow condition.

    The Caleffi 573 does have a spring check on the outlet, right below the gauge in this pic, basically the same check you find in most BFD. So with a combo fill/ BFD 573 on the left, you get 3 check valves and vent to atmosphere.

    There are markets in the world where that check in the fill valve is considered a BFD.

    Screenshot 2025-12-31 at 11.43.52 AM.png
    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream
  • Blend9684
    Blend9684 Member Posts: 16

    Thanks. I was looking at the non-combo Caleffi 553 with gauge. My assumption was that anything downstream of the BFD didn't have to be lead-free.

    I have a Legend S-459 which isn't lead-free (planned to return in favor of a Matco-Norca BFP-90-1/2LF or equivalent that was).

    My theory, and likely overthinking, is that the BFD is connected to potable water and might want to be lead-free as my "bridge." Then anything after doesn't have to be.

    But, similar to an outdoor spigot, I don't see how water makes it back across as you mention, especially since I'm now looking at three check valves.

  • hot_rod
    hot_rod Member Posts: 26,720

    Hydronic side components do not need to be LL. But more and more brass is going LL as it is a hassle to manufacture both standard brass and LL. All the tooling in the factory needs to be changed, lubricants, machine shavings segregated, , etc.

    I see some online suppliers now have a disclaimer if you but leaded brass valves and parts.

    Screenshot 2025-12-31 at 12.23.14 PM.png

    At days end it takes a fairly specific water condition to allow lead to leach out, Flint, MI for example. Most water piping and valves develop a "patina" inside within days that could prevent lead for leaching out.

    But the genie is out of the bottle now, so…

    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream
  • EBEBRATT-Ed
    EBEBRATT-Ed Member Posts: 19,721

    Anything after the backflow is heating pipe. Before the backflow it is plumbing.

  • mattmia2
    mattmia2 Member Posts: 15,739

    if i am reading the michigan residential code right, only things supplying drinking and cooking water need to be low lead so the boiler feed does not need to be low lead

    image.png
  • EBEBRATT-Ed
    EBEBRATT-Ed Member Posts: 19,721

    @mattmia i doubt any inspector will let that fly. They want anything in the potable water to be lead free.

    That would mean you don't need lead free in a bathroom or outside faucet or the dishwasher, washing machine etc.?

  • mattmia2
    mattmia2 Member Posts: 15,739

    exactly. none of woodford's stuff is low lead.

  • hot_rod
    hot_rod Member Posts: 26,720

    outdoor faucets are supposed yo have vacuum breakers installed. Many are built in now

    DW and washers have solenoids, those would need to fail, and I think fill is above overflow level?

    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream
  • mattmia2
    mattmia2 Member Posts: 15,739

    clothes washer usually have an air gap built in to the inlet to the tub. i'd assume dishwashers do too but i have never taken one that far apart. but my point was that woodford silcocks are widely used and they are not lead free so it would seem that they are accepted as that part of the system is not water used for cooking or drinking(although i have seen lots of travel trailers in a driveway hooked up to a silcock).

  • yellowdog
    yellowdog Member Posts: 283

    Silcocks in Vermont are required to be lead free.

Categories