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Two water temps, one boiler

cnmdesign
cnmdesign Member Posts: 102
Is it possible to get 175 degree water to zone 1 for hot water heater and 110 degree water to zone 2 for in ceiling trv radiators without using a mixer? I have a 89K Burnham K2 with Taco 404-4 valve control box.
Combat Veteran owned, Final Salute LLC on FaceBook & Twitter.
www.afinalsalute.com

Comments

  • EBEBRATT-Ed
    EBEBRATT-Ed Member Posts: 11,999
    No, you need some type of mixing valve, electric, thermostatic there are many types. They make non electric thermostatic valves.
    cnmdesign
  • hot_rod
    hot_rod Member Posts: 16,304
    Why so hot, 175 in one zone? Seems like a better application for a cast boiler?
    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream
    cnmdesign
  • Ironman
    Ironman Member Posts: 6,868
    edited May 2020
    The K2 comes with a provision for connecting an indirect that provides priority to it and operates the heating for it at a different SWT than the space heating. All the controls needed for that are built into the boiler.
    You accomplish it with a separate loop and circulator for the indirect, not a zone valve. The pump and the indirect's aquastat connect directly to the boiler, not the ZVC.
    Bob Boan
    You can choose to do what you want, but you cannot choose the consequences.
    cnmdesign
  • cnmdesign
    cnmdesign Member Posts: 102
    I now have four zones, zone one is priority to the DHW (175) and the other 3 for heating (110). Caleffi zone valves and an ECM. If I can use this setup somehow, I would rather put on it's own loop with it's own pump.
    Combat Veteran owned, Final Salute LLC on FaceBook & Twitter.
    www.afinalsalute.com
  • HVACNUT
    HVACNUT Member Posts: 4,593
    edited May 2020
    The water heater is currently wired through the Taco board and has it's own zone valve?

    If that's the case then do as @Ironman said. Use the PCB System Pump output for space heat, and the PCB DHW Pump output for the indirect. Set temperatures accordingly.
    You'll either have to remove the zone valve for the water heater or rewire it so it's not going through the Taco board. And it needs a dedicated circulator of course.
    cnmdesign
  • Ironman
    Ironman Member Posts: 6,868
    Here's a link to the I/O manual:

    https://file.ac/LXl6EwjtYzo/K2WT I&O Manual.pdf

    There are a couple of methods shown for piping an indirect with that boiler around pages 75 - 76.
    Bob Boan
    You can choose to do what you want, but you cannot choose the consequences.
    Zmancnmdesign