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Navien NCB240/130H w/ zone controller

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Tallred
Tallred Member Posts: 4
in Radiant Heating

I recently replaced my old tank water heater that was used to heat my radiant system with the navien combi boiler. I'm trying to understand how to connect my valve controller to the boiler.

The controller is an I-link which powers the circulator pump and valves.

1000009756.jpg

Do I wire from the Zone 1 location on the controller to the boiler? Where do I land on the boiler? TT or Zone 3?

The controller has a master/slave switch. It is currently set as master. When wiring to the boiler would I need to switch to slave?

1000009757.jpg

Any help would be appreciated.

Comments

  • 109A_5
    109A_5 Member Posts: 3,684
    edited January 11

    What is the I-Link controller model ?

    So no buffer tank and no DHW indirect tank ?

    Master / Slave is probably if there is more than one I-Link controller.

    National - U.S. Gas Boiler 45+ Years Old
    Steam 300 SQ. FT. - EDR 347
    One Pipe System
  • hot_rod
    hot_rod Member Posts: 27,056
    edited January 11

    that may be an Azel brand control, the wiring should be similar to this, or go to the Azel site for and earlier version wiring schematic

    There should be a NO , normally open, and C common connection to wire the boiler TT connection. 2 conductor thermostat wire is fine.

    The priority dip switch to off if you don’t have an indirect

    IMG_1367.png
    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream
  • 109A_5
    109A_5 Member Posts: 3,684

    Looks like the boiler wants T/S_ZONE3, although in your situation it may not matter much. Apparently Zone 3 is also for the System Pump. However your I-link may control that already.

    image.png
    National - U.S. Gas Boiler 45+ Years Old
    Steam 300 SQ. FT. - EDR 347
    One Pipe System
  • Tallred
    Tallred Member Posts: 4

    Controller is model SZ-V6.

    There is a buffer tank on both DHW and radiant sides.

  • hot_rod
    hot_rod Member Posts: 27,056

    There should be a wiring diagram inside the cover of the control?

    Now if you have a buffer tank, often times the control on the buffer tank runs the boiler, via TT from the tank aquastat.

    So we need the entire system info, maybe a pic of the piping to try and understand what control logic is needed.

    A buffer on the heat side and an indirect?

    Different controls use different terminals for indirect tank connection. Caleffi is always relay one in any box. I think Taco is always the last relay in the box, so you need the info on your exact controller to get the indirect connected to the correct output, if you have one?

    I can't quite see if this priority switch is on or off? It would seem to indicate indirect priority is zone 1.

    Screenshot 2026-01-11 at 8.59.49 AM.png
    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream
  • 109A_5
    109A_5 Member Posts: 3,684
    edited January 11

    Umm… Is there an aquastat on either or both tanks ?

    Doesn't that boiler provide on demand DHW ?

    National - U.S. Gas Boiler 45+ Years Old
    Steam 300 SQ. FT. - EDR 347
    One Pipe System
  • 109A_5
    109A_5 Member Posts: 3,684
    image.png

    https://azeltec.com/images/SZV6instruction.pdf

    National - U.S. Gas Boiler 45+ Years Old
    Steam 300 SQ. FT. - EDR 347
    One Pipe System
  • Tallred
    Tallred Member Posts: 4

    The diagram from azeltec.com matches what I have. If I'm reading that correctly, I can wire from X1 X1 to zone 3 on the boiler. Am I correct? The zone controller does control the circulating pump.

    If I understand this correctly, the controller will start the pump and request hot water when a valve is open, dropping the signal when the valve closes.

    I'm going to check voltages but my understanding is I connect to the NO point on the boiler. Is that right?

  • 109A_5
    109A_5 Member Posts: 3,684

    I'm a bit confused on your system's intended topology.

    Are you going to use the boiler's DHW features to preheat the water going into the indirect tank ? Not having water in the DHW piping of the boiler may damage it.

    For the radiant, often the buffer tank's aquastat controls the boiler not the zone controller.

    National - U.S. Gas Boiler 45+ Years Old
    Steam 300 SQ. FT. - EDR 347
    One Pipe System
    hot_rod
  • Tallred
    Tallred Member Posts: 4

    Thanks for the help. I've been away for the last week.

    I got everything hooked up today and it's working. Thanks for the help.

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