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cast iron boilers

Thanks for responding Brian. Is the 20 degree delta T coming directly from Smith? Do you have any information on the correct start up procedure? Thanks.


  • William Cameron
    William Cameron Member Posts: 2
    minimum temperature for cast iron boilers

    What is the minimum operating water temperature (supply and return) for today's cast iron boilers? 140, 130 discharge?
  • Dave_12
    Dave_12 Member Posts: 77

    Smith Cast Iron Boilers recommend 140 F minimum for return water. Maximum of 20 degree temperature differential.
  • Guy_6
    Guy_6 Member Posts: 450

    A 20 degree delta is ideal, but we at Smith will ALLOW up to a 40 degree delta. That being said, under normal circumstances, 140 is the minimum return water temp. allowed.
    The recommended startup procedure would be fairly straightforward industry wide:
    Check combustion (with instruments) and adjust as necessary, and check that those water temps are where they should be. Document everything.

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