Welcome! Here are the website rules, as well as some tips for using this forum.
Need to contact us? Visit https://heatinghelp.com/contact-us/.
Click here to Find a Contractor in your area.

Taco Zone Valve ZVC 404-4 Installation Help

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


    HVACNUT Member Posts: 4,592
    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?
  • SteveSan
    SteveSan Member Posts: 117
    Good afternoon Eric, here is the link for the wiring diagram. http://apps.taco-hvac.com/uploads/FileLibrary/102-393.pdf. 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.
  • unclejohn
    unclejohn Member Posts: 1,757
    Do you want the smart stats for night setback? Probably not worth the money for the little savings if any you would get.
  • EricM_NJ
    EricM_NJ Member Posts: 2
    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