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2 Zone Heat Questions

fljjmarz
fljjmarz Member Posts: 5
Hi, I have Weil-McLAin CGa Gold furnace. Model number on the “motherboard” inside the unit is 1135-605.

Can this unit be wired to have 2 zones?
If so, is there a standard wiring diagram I could follow?
Thanks in advance
Frank

Comments

  • fljjmarz
    fljjmarz Member Posts: 5
    bump
  • GroundUp
    GroundUp Member Posts: 1,495
    It's as simple as adding a switching relay or zone valve controller, depending on what you want to zone with. The wiring diagram does not show an option for multiple zones without external controls.
  • fljjmarz
    fljjmarz Member Posts: 5
    Thanks for the reply!
    There is only one input for a single thermostat on my furnace.

    Can both thermostats be wired to this one input, or adding a zone can only be done with an external zone valve controller?
    Frank
  • pecmsg
    pecmsg Member Posts: 3,538
    How are you controlling these zone, 2) circulators or zone valves?
  • GroundUp
    GroundUp Member Posts: 1,495
    Exactly- it needs an external control. Switching relay for zone pumps, zone valve controller for zone valves (Taco SR502 or ZVC403 are what I'd use), and the end switch from that control would get wired to your boiler's thermostat terminals while each thermostat is wired to the ecternal control- not directly to the boiler.
  • fljjmarz
    fljjmarz Member Posts: 5
    pecmsg: I'm using 2 Zone Valves with 1 circulator

    GroundUp: So the two thermostats are wired into the Zone Valve Controller (relay), and from there go to the 2 zone valves and the furnace.

    Thank you
  • pecmsg
    pecmsg Member Posts: 3,538
    The zone valves will have a switch that closed to the boiler.
  • EdTheHeaterMan
    EdTheHeaterMan Member Posts: 4,935
    edited October 2022
    When using Zone Valves, you need to select a Zone Valve with an End Switch. Usually 3 or 4 wire zone valves have such a switch. The contacts of the switch on a zone valve will close (similar to the contacts on a thermostat) when the valve is completely open. By wiring the end switch from each valve in a parallel configuration (see terminal 2 and 3 of each valve in the diagram) to the thermostat location on the boiler, you will get the desired result.
    Edward Young Retired HVAC Contractor & HYDRONICIAN Services first oil burner at age 16 P/T trainer for EH-CC.org
  • fljjmarz
    fljjmarz Member Posts: 5
    Thanks Ed, so your method & diagram is without a Zone Valve Controller
  • EdTheHeaterMan
    EdTheHeaterMan Member Posts: 4,935
    fljjmarz said:

    Thanks Ed, so your method & diagram is without a Zone Valve Controller

    With only 2 Zone valves, the wiring is quite easy. When you get to 3 and above, then I encourage the Taco ZVC or any other brand of your choice.
    Just keep your wires neat and clean and easy to follow for future problem troubleshooting. Like this photo

    Edward Young Retired HVAC Contractor & HYDRONICIAN Services first oil burner at age 16 P/T trainer for EH-CC.org