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Aquastat alternatives?

rbphhc
rbphhc Member Posts: 127
edited March 2023 in THE MAIN WALL
Any newfangled ways to set hi/lo limits to trigger a circ pump? I dimly remember using Chinese PIDs and relays back when we had a boiler running on veggie oil...

Digital readouts and precise set points would be nice. Aquastats seem designed for fairly narrow differentials. May need to go 30°f+ here. Thx!


Comments

  • dko
    dko Member Posts: 668
    A single delta-t circ like the taco vt2218 using two temp probes
    rbphhcSuperTech
  • STEVEusaPA
    STEVEusaPA Member Posts: 6,505
    How about some more details. What do you have, what are you trying to accomplish?

    There was an error rendering this rich post.

    rbphhc
  • rbphhc
    rbphhc Member Posts: 127
    edited March 2023
    STEVEusaPA said:

    How about some more details. What do you have, what are you trying to accomplish?

    Trying to maintain indirect between 140 high and 120 low.

    Indirect is acting as buffer tank for direct DHW storage (NTI S20W 20gal).

    Circ pump is a Taco 006e3, but could be upgraded.
  • rbphhc
    rbphhc Member Posts: 127
    dko said:

    A single delta-t circ like the taco vt2218 using two temp probes


    Nice pump. But this is circulating DHW, so needs to be SS, bronze, or composite.
  • rbphhc
    rbphhc Member Posts: 127
    Found this on an older thread:


  • rbphhc
    rbphhc Member Posts: 127
    edited March 2023
    One issue is that the NTI indirect comes with its own temperature probe, but no T-stat (unlike an Amtrol, etc).

    A circulator aquastat (Honeywell, etc) has its own single-wire probe. That could be used if I don't use the NTI sensor.

    Ideally I'm looking for something that can take the 2-wire feed off the NTI probe, that's programmable for hi and low limits, and will trigger the circ pump on and off.

    Sensor link here: https://static1.squarespace.com/static/575837b259827e26b5694200/t/612905859a31560073d3a11f/1630078342517/TASSERON+CABLE+TEMP+SENSORS.pdf


  • hot_rod
    hot_rod Member Posts: 23,382
    My go-to electronic setpoint control.
    If you want variable speed, the solar differential controllers can be set point, differential and variable speed.
    Data logging BTU metering, etc
    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream
    rbphhc
  • rbphhc
    rbphhc Member Posts: 127
    hot_rod said:
    My go-to electronic setpoint control. If you want variable speed, the solar differential controllers can be set point, differential and variable speed. Data logging BTU metering, etc
    Nice dude! Thanks!
  • ratio
    ratio Member Posts: 3,789
    +1 on the ETC, it's cheap & flexible. Also Honeywell T775 series, bigger 'n better. If you're into programming, there's https://www.datanab.com/products/mbus_io12_lcd-fully-programmable-modbus-i-o-device-with-lcd-display. Fun to play around with, I've seen them used in the wild by OEMs.
    rbphhc
  • rbphhc
    rbphhc Member Posts: 127
    https://forum.heatinghelp.com/discussion/comment/1743470#Comment_1743470

    Looks like that DataNab thing could handle both circ and recirc duties?

  • ratio
    ratio Member Posts: 3,789

    I don't see why not. You can download the free version of the software, write the program, & even simulate it before you shell out.

    rbphhc

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