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Can I bypass TACO ZVC406-4

Gary1212
Gary1212 Member Posts: 3
in Gas Heating
All lights are rapidly flashing yellow and no zones are working.
Power is good. Gas is fine. Assuming the unit is bad.
The Big Question: How can I bypass the TACO ZVC406-4 unit to allow zones to operate until the unit can be replaced?

Comments

  • Zman
    Zman Member Posts: 7,611
    If you put a jumper wire from R to W on the t-stat connections does it work?
    What type of zone valves do you have?
    You should be able to manually open the zone valves and manually enable the boiler to get this running.
    A picture of the zone valve and the inside of the controller would help.
    "If you can't explain it simply, you don't understand it well enough"
    Albert Einstein
    STEVEusaPA
  • Shane_2
    Shane_2 Member Posts: 194
    I might suggest checking for a short, zone valve wiring and thermostats. Then check the fuses on the board, there may be spare fuses on the cover as well depending on the manufacture date.
  • STEVEusaPA
    STEVEusaPA Member Posts: 6,505
    Sometimes wifi (Nest) thermostats can cause this. Also if there was some kind of short that damaged the control, replacing the control might only be an exercise in futility.

    There was an error rendering this rich post.

    Tinman
  • Gary1212
    Gary1212 Member Posts: 3
    edited December 2021



    Thank you for the input everyone. I'm a homeowner with basic 'hanyman' skills and sophisticated electrical is not my specialty. What I'm hoping to find is a way to:
    1) Manually open a zone valve (I got that figured out), and;
    2) Manually kick the boiler (Weil-McLain GOLD GV) on to provide heat until I can have a PRO come out.

    Zman: I've attached pics of what you asked for; any suggestions and/or help much appreciated.
  • Zman
    Zman Member Posts: 7,611
    edited December 2021
    If you take the 2 wires that are presently attached to "X-X Primary end switch" and wire nut them (or put them both on the same terminal), the boiler will fire.

    Are the fuses to the left intact?
    "If you can't explain it simply, you don't understand it well enough"
    Albert Einstein
    TinmanGary1212
  • Tinman
    Tinman Member Posts: 2,808
    What Zman said. Clean work, nice to see.
    Steve Minnich
  • Gary1212
    Gary1212 Member Posts: 3
    Zman...Thank you! You are the man; Zman, I mean.
  • STEVEusaPA
    STEVEusaPA Member Posts: 6,505
    If all the lights are flashing I would start by first removing thermostat wires (top terminals), one zone at a time to see if that stops it.
    If so, you know where to continue looking.
    If not, reconnect thermostat wires, and then disconnect zone valve wires, one zone at a time to see if that stops it.

    There was an error rendering this rich post.

  • SteveSan
    SteveSan Member Posts: 260
    @gary1212 please give us a call at your earliest convenience. We can help you troubleshoot your zvc control. What type of t-stats do you have? Please call 401-942-8000 Mon-Fri 8am-5pm EST.
  • Dave H_2
    Dave H_2 Member Posts: 587
    First question, has it worked in the past? New install? or has anything changed if it did work? (sorry bout that, it's actually three) B)

    Dave H.

    Dave Holdorf

    Technical Training Manager - East

    Taco Comfort Solutions

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