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Primary Secondary with and On Demand Water Heater

Is Primary Secondary a good Idea for piping an on demand water heater?  Can I just use it like a boiler?  what are the design considerations that I should be thinking about?


  • meplumber
    meplumber Member Posts: 678
    Not recommended.

    An on demand water heater is not rated for use as a central heating appliance.  We all have horror stories of trying to repair/replace "newer" installations, where the water heater can't perform.  It is not designed to be used in that manner.

    Most jurisdictions have outlawed their use as a central heating appliance.  Meaning that it will not pass an inspection.

    Don't do it.  Get a real boiler.  The gas mod/cons piped primary secondary will do the job as designed.

    Good Luck.
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