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

zvc pump problem

bmanbman Member Posts: 2
I have a tacozvc-404-2 and trying to wire uponer two wire zone valves. my problem is that the zone valves open fire when t stat is calling but zone controll box dosent see that there open also how do you wire the circ pump to fire when zone is calling


  • Gary Jansen_4Gary Jansen_4 Member Posts: 73
    ZVC reply

    Install a jumper across terminals 3 and 4 of the zones you have thermostats connected to. Wire 120 volt hot to one side of end switch, other side of end switch to pump. Neutral wire goes directly to pump. Set mode switch to normal. Priority switch to off. That should get you going. 
  • Tim McElwainTim McElwain Member Posts: 4,397
    HI Gary Jansen

    it  has been a while since I have seen your name posting here, how are you doing?
  • Gary Jansen_4Gary Jansen_4 Member Posts: 73
    Well Tim, it's like this

    I'm still fat and sassy

    I'm still living the dream

    and every day is a day in paradise!

    At least the 1st one is true.

    Thanks, Gary
  • Joe MattielloJoe Mattiello Member Posts: 597

    The zvc404 is the facilitator for the multiple thermostats, and corresponding zone valves.  When the thermostat closes, TT close to energize the zone valve.  The end switch from the valve when wired to the 3, and 4 terminals communicates to the control the valve is open it's OK to fire the boiler and energize the system pump. 


    The system pump can be wired to the extra end switch.  the wiring schematic is found on the instruction sheet about midway down on the left hand side.  Hopefully this helps. 
    Joe Mattiello
    N. E. Regional Manger, Commercial Products
    Taco Comfort Solutions
This discussion has been closed.


It looks like you're new here. If you want to get involved, click one of these buttons!