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Taco Zone Valve ZVC 404-4 Installation Help

EricM_NJEricM_NJ Posts: 2Member
I currently have a 3 zone hw Utica boiler with 3 thermostats, 3 Honeywell 4 wire zone valves, 1 24 volt transformer, 1 acquastat relay, 1 circulator pump. Everything is wired and working properly. I would like to eliminate the 24 volt transformer and introduce a taco 404-4 zone valve controller so I can add a common wire to each of the thermostats for smart thermostat upgrades. Based on the taco wiring diagram I am confident I have everything properly mapped out except for the circulator pump. Can someone identify for me where the hot and nuetral, and ground wire from the pump should connect to in the valve controller? I appreciate the help. Thanks


  • HVACNUTHVACNUT Posts: 2,838Member
    In the diagram the system pump HOT goes through the End Switch XX terminals on the lower left side of the board.
    One X terminal is always 120v powered. The second X gets wired to the system pump hot. The neutral and ground can be picked up in the zone board.
    XX is simply a switch to turn the circulator on and off.
    What are you using for domestic hot water?
  • SteveSanSteveSan Posts: 47Member
    Good afternoon Eric, here is the link for the wiring diagram. The hot from the pump would go to the right X of the pump end switch and bring a jumper from line hot to the left X of the pump end switch. Neutral would get tied together with the neutral coming in and there is a place for the ground on the zvc control. If you have any questions please call into Taco Tech Support 401-942-8000 we are here Mon-Fri 8am-5pm.
  • unclejohnunclejohn Posts: 1,448Member
    Do you want the smart stats for night setback? Probably not worth the money for the little savings if any you would get.
  • EricM_NJEricM_NJ Posts: 2Member
    Than you all for your guidance. It all makes sense now. For domestic hw i have a separate tankless NG on demand hot water heater . I works great. I plan on using the smart thermostats to control the heat when I am away as well for starting it up when I’m on my way home. I am looking forward to adding this zone valve controller. I will probably add an outdoor temperature reset as well in the future to lower the boiler temperature on those not so cold days. Thanks again
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