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120V to Taco ZVC404-4

I am excited to install my Taco ZVC. I have a Peerless boiler, indirect water heater and 4 zones (3 heat, 1dhw).
My plan is to mount the unit to the boiler casing and run all the Tstats and zone valves to the appropriate ports. I will then run low voltage wiring from the end switch on the ZVC to TT on my aquastat, which will run our circ pump during calls for heat.

My question is in regards to the 120v required for the ZVC404-4. I am curious as to which is the best method for pulling this in. I have a line coming into a junction box on the right side of the boiler casing that feeds the aquastat and circ pump. Not sure if I should jump off of that wiring and run some 14/2 armored right out of that box or if that would overcrowd it.


    HVACNUT Member Posts: 5,887
    edited October 2018
    I dont know the number wires allowed in a 1900 box (4" square).

    Power, 120 in, splice to power the aquastat, splice from the aquastat to the circ.
    What model aquastat? An L8124 or L8148 should have C1,C2 to power the circ direct without going through the 1900 box.

    If that's all the wiring in the 1900 box, there shouldn't be a problem adding the ZVC.
    If needed, they do make extensions for the 1900 box though I dont know if the big box guys will stock it.

    Use the 120v line in from the emergency switch (E. switch on the 1900 box?) plus the neutral and ground of course to power the ZVC.

    If theres room underneath the 1900 box for the ZVC, get a 1/2" offset chase nipple and locknuts to connect knockout to knockout for a clean look.
  • kevinbrandon
    kevinbrandon Member Posts: 5
    Thank you for the quick reply. I've attached some photos of my boiler/junction box on the right side and the aquastat.

    The aquastat is a L7224U 1002.

    A little hard to see the wiring to the aquastat but I thought I'd mention that it is feeding power to the circ pump.

    It seemed a little odd to me that the aquastat is wired as followed but then again, the system has been operational.

    Circ pump Neutral to L2 on Aquastat
    Circ pump Hot to C1 on Aquastat

    Can I tie into the 120 anywhere at the jbox or before it gets there?

    Thank you.

  • STEVEusaPA
    STEVEusaPA Member Posts: 6,505
    I think you should extend the box like @HVACNUT suggested.

    There was an error rendering this rich post.

  • kevinbrandon
    kevinbrandon Member Posts: 5
    Thank you for the guidance. I extended the box and wired the hot line in after the e switch and the neutral to neutral. There was not a ground available. Progress thus far...