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[TACO ZVC40X] - Boiler + Pump Control?

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Hello Controllers... :smiley:

Updating my 5 zone system that currently consists of 2 transformers and a lot of wire nuts to use two 4 zone TACO zone controllers (I wanted two of the expandable 4 zone ones because I want to add a 6th zone and an indirect water heater so I need 7 total...)

Anywho, wiring is pretty strait forward since all of the TStats come to a central box right now, I can easily wire them into the zone controllers. I can also easily run 120 to each zone controller, and the wiring to the zone valves is also very strait forward.

My question then comes from what is currently wired to the end switches, which signals a boiler control to turn on the pump, and is on the same board that takes signal from the aquastat and controls the boiler.

Photo of inside of said control (wire coming from the current cluster of wires connecting into the top left):

Boiler Control box


Should I just leave that all as it is and tie the wire coming out to the end switch "Main" on top of the taco? Or should I pull 120 up to the TACO for the pump and use the PUMP END SWITCH on the bottom of the board?

My gut is to just leave it as is, but perhaps I am missing out on something if I do?

Thanks!

Comments

  • iced98lx
    iced98lx Member Posts: 68
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    "It worked when I was done"


    So much for trying to do it a little at a time. I guess I just mass disconnect and GO FOR IT.
  • HVACNUT
    HVACNUT Member Posts: 5,865
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    TV and T is the end switch in the aquastat. 
    You would simply wire it in parallel to the XX isolated end switch terminals on the ZVC's. Nothing else needs to be done, except, remove the White wire from the Z terminal and cut and cap it. It also looks like the low volt is coming through the same connector as the line volt wires. That's an accident waiting to happen. Bring the low volt through the top knockout. 
    The zone valves end switches go to their corresponding 3 and 4 terminals in the ZVC's.
    It's not a must, but that aquastat is pretty old, and obsolete. Look into upgrading to a Hydrostat 3200 Plus or similar. 

    STEVEusaPAiced98lx
  • iced98lx
    iced98lx Member Posts: 68
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    HVACNUT said:

    TV and T is the end switch in the aquastat. 
    You would simply wire it in parallel to the XX isolated end switch terminals on the ZVC's. Nothing else needs to be done, except, remove the White wire from the Z terminal and cut and cap it. It also looks like the low volt is coming through the same connector as the line volt wires. That's an accident waiting to happen. Bring the low volt through the top knockout. 
    The zone valves end switches go to their corresponding 3 and 4 terminals in the ZVC's.
    It's not a must, but that aquastat is pretty old, and obsolete. Look into upgrading to a Hydrostat 3200 Plus or similar. 

    Thank you for chiming in and trying to help, I appreciate it. I do not fully understand your instructions so I'm going to try to figure things out a bit better:
    • The Red & White wires coming from the aquastat (T / TV I believe) require 24v applied to them to activate the circulator pump.
    • Currently I have an additional 24v transformer with positive running to the Aquastat red, the white ran through the ZVC "END SWITCH MAIN" relay, and it works as expected, zones light up, the end switches open, voltage is applied to the aquastat and it starts circulating
    • I would like to get rid of the additional external 24v transformer, but I don't follow your suggestion of using the XX isolated terminals, aren't those 120v?
    • I'm looking into the 3200 for a post-christmas upgrade.
    Thanks for the patience helping a newbie out.
  • iced98lx
    iced98lx Member Posts: 68
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    Scratch that all @HVACNUT I went and did more reading and realized I need to put the red + green wires from the Aquastat on the relay, thus your note to "Cap the white".

    Makes sense as soon as I realized that of course there is a 24v transformer in the aquastat.

    Thank you for the help!!!!
  • iced98lx
    iced98lx Member Posts: 68
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    I did finally get the 2nd ZVC wired up in slave mode for the one zone that currently resides on it and all is working perfectly. Really appreciate this board's willingness to help! Now I'm ready for the water heater and master bathroom zones to be added!
  • iced98lx
    iced98lx Member Posts: 68
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    This portion of the bigger project is done outside of wire staples. More to do overall, obviously.
  • HVACNUT
    HVACNUT Member Posts: 5,865
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    Glad you got it straightened out. 
    It's hard to tell the depth between the flue and the zone panels. Even if there's room to work, it's still an awkward location for service. 
    I would relocate them. Drill holes in the plywood and bring the wires in through the back for a neat appearance. 
    STEVEusaPAiced98lx
  • iced98lx
    iced98lx Member Posts: 68
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    HVACNUT said:

    Glad you got it straightened out. 
    It's hard to tell the depth between the flue and the zone panels. Even if there's room to work, it's still an awkward location for service. 
    I would relocate them. Drill holes in the plywood and bring the wires in through the back for a neat appearance. 

    It's really tight and super annoying to work around the flue and the supply lines, my plan is to build a new wall about where I'm standing to take the photo to mount the new modcon natural gas boiler on and have better organization there....
  • iced98lx
    iced98lx Member Posts: 68
    edited January 2021
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    HVACNUT said:

    It's not a must, but that aquastat is pretty old, and obsolete. Look into upgrading to a Hydrostat 3200 Plus or similar. 

    Well, I ordered a 3200 Plus, I think we're going to convert this old girl to NG and try to get through at least this winter with it vs rushing to put in a new mod con.

    Since getting the zone controllers in place everything has worked flawlessly and tbh the house is extremely comfortable. The flue pipe is horribly done and illegal but does seem to be effective. I've littered the entire path of the flue with carbon monoxide and combustible gas alarms, so far so good.

    This will give us time to really consider which boiler best fits our needs and do the indirect water heater to match.
  • iced98lx
    iced98lx Member Posts: 68
    edited January 2021
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    HVACNUT said:

    It's not a must, but that aquastat is pretty old, and obsolete. Look into upgrading to a Hydrostat 3200 Plus or similar. 

    Look at what you've started.



    I just got the 3200 fired up so we've got 3 zones demanding heat (off for an hour while I fiddled and it's 20 degrees outside..) but I'm looking forward to seeing if we save any propane!

    I saved the electro-well install for the spring when I can drain the boiler without fear of mutiny from the family.
  • iced98lx
    iced98lx Member Posts: 68
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    Well just overnight I can say the various zones stayed the called for temperature with no noticed change by anyone, the basement however (1100 sqft, unfished, has 1 radiator which steals from the room above) which was normally kept nice and toasty by the boiler is now freezing! Seems like a good thing (less propane being burned to keep the basement hot). Happy with anything that nets me a 12 month ROI on the HydroStat!

    Now on to combustion tuning/measurement which will happen when this gets converted to natural gas.