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Wiring Taco SR501 with Taco ZVC406

Please bear with me, I am just a DIY'er learning heating controls.

I have a gas fired boiler with its own circulator (Circ A) and an indirect hot water heater.
I currently have 3 zones with 3-wire zone valves and a circulator (Circ B ) being controlled by an SR501.
I installed 4 new zones, a manifold with 2-wire thermal actuators, and an additional circulator (Circ C). I plan to remove 2 of the old zones (baseboard) but keep one zone (slab loop).
I purchased a ZVC406 with priority for the new zones.

I would like to control the 4 new zones, the new circulator and my hot water heater (priority zone) with the ZVC406.
Should I control the old slab zone and circulator with the SR501 or eliminate the SR501 and wire them to the ZVC406? If I wire the old slab zone and circulator to the ZVC406, how do I wire the pumps so it doesn't come on when any zone calls for heat, only when the slab zone calls for heat?

If I keep the SR501 to control the single zone, how do I connect a three wire zone valve for the single radiant loop to the SR501? What happens when both the SR501 and ZVC406 activate the boiler Thermostat at the same time? Will this cause any issues?

I can supply diagrams if needed.
Basically, I'd like 4 zones to control Circ A and C, while one zone controls Circ A and B. Not sure how to accomplish this.


    HVACNUT Member Posts: 5,863
    Who's on first?

    Some pics would be awesome.

    Forgive me because I'm a very stupid man but I can't figure out how many circs there are now, how many zone valves, which circ(s?) are powered by said zone valves, how many total heat zones, the indirect for priority, but has it's own circ, and or zone valve?

    The last paragraph,
    You want 4 zones to control circs A and C, while one zone controls circs A and B. Do you mean 4 thermostats?

    Please post some pics and describe your intentions with a visual stimulant.
  • Jamie Hall
    Jamie Hall Member Posts: 23,438
    edited October 2018
    Some arrangement of relays is going to do the job -- but you really do, as @HVACNUT says, clearly define first exactly what is supposed to control what. It doesn't sound all that conventional... you might consider writing it out as a table (as well as a diagram) which lists exactly what pumps and valves are supposed to operate with which thermostats...
    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England