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Additional Zone & Circulator question

Hi all,
We've got three circulators powered by our NTI TFT boiler (Primary, Secondary and Indirect DHW).
We're looking to adding baseboard heating to the basement as a separate zone (tees were provisioned off the primary loop for this eventuality), but the boiler seems to only accommodate those three circulators, should I double up this new circulator into the power-source currently supplying the Secondary loop circulator? Or should I just have it on a switch and run it constantly during heating season? Happy to provide more info about the system - boiler is running off an outdoor reset,
Cheers,
Mike

Comments

  • HVACNUT
    HVACNUT Member Posts: 4,188
    You'll have to purchase a 2 zone, zone control board. Wire your new zone line and low volt to it, Remove the space heating zone wiring (circ. and thermostat) from the boiler and bring it to the new zone board.
    Wire low volt from the set of dry contacts (XX) in the zone board to the thermostat wiring on the boiler. The DHW and primary pumps stay as is.
    HydronicRookie
  • newagedawn
    newagedawn Member Posts: 586
    or you could get a single zone relay, for the single zone and wire it accordingly, with t stat and line voltage to a separate calculator
    "The bitter taste of a poor install lasts far longer than the JOY of the lowest price"
    HydronicRookie
  • j a_2
    j a_2 Member Posts: 1,796
    Don't forget the all important low water cutoff if not already installed.....required when piping below boiler
    HydronicRookie
  • Ironman
    Ironman Member Posts: 6,555
    Don't you currently have C.I. rad's? I also remember you posting about adding a radiant floor zone. Both of those would require a different water temp zone than fin tube BBs.

    You may get by over-sizing the BB if it's on a separate zone, but more info about your system is needed. Can you post some pics of what you actually have?
    Bob Boan
    You can choose to do what you want, but you cannot choose the consequences.
    HydronicRookie
  • HVACNUT
    HVACNUT Member Posts: 4,188
    > @newagedawn said:
    > or you could get a single zone relay, for the single zone and wire it accordingly, with t stat and line voltage to a separate calculator
    >
    >
    >> In that application, what would fire the boiler if a SH zone thermostat is already connected to the boiler thermostat terminals?
  • newagedawn
    newagedawn Member Posts: 586
    the aquqstat would, when the zone calls circulates the water aquastat temp gets low and comes on provided its a triple aquastat
    "The bitter taste of a poor install lasts far longer than the JOY of the lowest price"
  • HVACNUT
    HVACNUT Member Posts: 4,188
    > @newagedawn said:
    > the aquqstat would, when the zone calls circulates the water aquastat temp gets low and comes on provided its a triple aquastat
    >
    >
    >> I'm not familiar with that boiler, but I think its a mod con and is a cold start with only one set of SH terminals.
  • bob eck
    bob eck Member Posts: 928
    Look at using Sterling Synergy copper baseboard designed to work with low water temp boilers. Or look at Heating Edge copper baseboard from Smith's Environmental HE2
    HydronicRookie
  • HydronicRookie
    HydronicRookie Member Posts: 54
    Hi all, sorry for the lag, I thought I had properly enabled notifications to go to my email. I'll just respond all at once...

    @HVACNUT @newagedawn, thanks for the relay tip - that's way better than doubling up on the boiler power source. I'll likely do single zone controller. What's a triple aquastat btw? SH zone/terminal? I'm thinking of using a themostat as a 'local' demand switch for the existing secondary zone.

    @j a Absolutely, luckily the Trinity TFT comes with a factory installed LWCO already

    Hi @Ironman, you've got a great memory, I'd left stubs for in-floor on my previous project but with all the other renos the basement remained as it was. I started a whole other hydronic project earlier this Spring, its all CI rads where I had to tie into existing CI headers (not wanting to drain the system), and now with the basement tenant moving out, we're looking to convert from electric baseboard. I still haven't fired up the boiler, and I still have to swap out the existing electric DHW for the installed indirect, but its getting close. Perhaps I should start another post with pictures for critique?
  • HVACNUT
    HVACNUT Member Posts: 4,188
    > @HydronicRookie said:
    > Hi all, sorry for the lag, I thought I had properly enabled notifications to go to my email. I'll just respond all at once...
    >
    > @HVACNUT @newagedawn, thanks for the relay tip - that's way better than doubling up on the boiler power source. I'll likely do single zone controller. What's a triple aquastat btw? SH zone/terminal? I'm thinking of using a themostat as a 'local' demand switch for the existing secondary zone.
    >
    >
    >> You can't double up on the boiler power source.

    > A triple aquastat doesn't pertain to your boiler. It's typically on an atmospheric boiler that maintains a minimum temperature.
    >
    > SH- space heating zone.

    > If you currently have one SH zone, the thermostat and circulator are wired directory into the corresponding tetminals in the boiler.

    If you want to add additional SH zones, the thermostat and SH circulator wiring get removed from the boiler and reinstalled in a 2,3...6 zone board relay along with your new zone(s).
    A 2 conductor low volt wire will go from a set of dry contacts in the zone relay (typically XX) to the thermostat terminals on the boiler. That way, when ANY SH zone call for heat, XX will close and complete the circuit to energize the boiler heat cycle.
    HydronicRookie
  • HydronicRookie
    HydronicRookie Member Posts: 54
    Ah I see! So each zone thermostat will energize it's corresponding circulator via the controller unit, and in turn, the controller will communicate to the boiler's 'local' demand input to, as you say, energize the boiler heat cycle. I guess the outdoor reset simply informs the boiler about the outside temp so it knows how hot to make the water, and the thermostats control the circulators via the zone controller.