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Which boiler ports for adding a tankless heat exchanger to a Williamson GSA-200?

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Jells
Jells Member Posts: 646

If I were to do this, which ports are the in and out to the coil added to for something like an Everhot? I'm getting a new install, and want to make possibly adding this in the future much easier by putting plugged tees in the appropriate ports. Seems like the condensate return and the drain D are the obvious candidates, but if there's one thing I've learned about steam, it's don't make assumptions! I would think the ports should optimally be further apart than these 2.

Screenshot 2026-02-09 133219.png

Comments

  • 4GenPlumber
    4GenPlumber Member Posts: 115

    Just get a weil mclain eg 55. If you want to add a domestic loop, you can add the coil at that time. That way you avoid using "mud" and you separate the boiler water from the domestic.

    STEAM DOCTOR
  • 4GenPlumber
    4GenPlumber Member Posts: 115

    Its the same boiler, just with the loop option (worth the money).

  • STEAM DOCTOR
    STEAM DOCTOR Member Posts: 2,584

    The Williamson has two, 2 1/2" return tappings. Only the one on the left side, shows up in the literature. But the other one is certainly there. Using a WM, with the coil, is certainly simpler, and eliminates the need for an additional circulator.

    4GenPlumber
  • STEAM DOCTOR
    STEAM DOCTOR Member Posts: 2,584

    The WM is more expensive. But the external coil is expensive, plus the circulator and piping… But if you're looking to kick the can down the road, then the Williamson is not a bad idea. Just make sure to take out the plug at the time of installation. The longer it's in there, the harder it could be to get out.

  • Jells
    Jells Member Posts: 646

    Which plug? Assuming the water would be pulled from a tee on the condensate return, would you have the coil return just drop from the top splashing into the boiling water? Somehow I thought that would be just wrong!

  • STEAM DOCTOR
    STEAM DOCTOR Member Posts: 2,584

    Right hand, 2.5" return tapping