Hardness for Tankless water heater

Discussion in 'Tankless Water Heater Forum' started by Technomystic, Sep 2, 2019.

  1. Technomystic

    Technomystic New Member

    Joined:
    Sep 2, 2019
    Location:
    Upper Midwest USA
    What hardness is safe to use in a Navien tankless. Chicago water is 8 grains and a Rinnai needs to be descaled annually (quite a pain).
    I am installing a softener in Indiana to treat well water with 14 grains hardness and 0.3 ppm iron.
    I would like to set my softener to conserve salt but it would result in 2-3 grains hardness.
    Would that clog my Navien with CaCl3?
    It might be cheaper and easier to just set the salt consumption higher to get <1 grain output than to have to descale the Navien.
    What is most efficient hardness please?
    Thanks
     
  2. Reach4

    Reach4 Well-Known Member

    Joined:
    Sep 25, 2013
    Location:
    IL
    If you set your softener to use 5 or (preferably) 6 lb/cuft of salt, you should do better than your 2 grains of leakage. You would still be getting reasonable salt efficiency.

    With the 6 lb/cuft it will make the water better than going leaner. 8 to 6 is the most popular range.
     
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