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zone valve control: Switching relay ?

TAG
TAG Member Posts: 788
in Radiant Heating
What's the best way to wire in a thermostat to control a zone valve ? Taco switching relay?

Had the Installers pipe in a zone valve to the 11 loop manifold for my retrofit plates -- It's a single 900sf living room, Since the whole house is running off one temp water this zone may never be needed .... I had them install the valve and wired for thermostat/ floor sensor just in case .... it will act as a high limit. The room is at the top of the building and open to the floors bellow -- so it gets additional heat.

The boiler is running on ODR -- this will be independent and have no other connections. Guess I have to figure out a way to turn it off in the summer ....

Comments

  • HomerJSmith
    HomerJSmith Member Posts: 2,640
    edited December 2020
    It depends upon what kind of floor sensor. Whether a switch or K resistor type that you are using as a high limit. What kind of thermostat? The thermostat is regulating heat delivery.

    I would not use a Taco switching relay if it could be avoided. I'm cheap and it is expensive and may not be needed.

    Your information provided is insufficient for me to make a recommendation.
  • Alan (California Radiant) Forbes
    Alan (California Radiant) Forbes Member Posts: 4,394
    Yes, that's a smart thing to do. A Taco or Caleffi zone valve control, but the smallest made is 3 zones I think. You could also go rogue and free-wire with a transformer, but I like the diagnostics of a proper control.
    In the summer, just switch your Viessmann to DHW only.
    8.33 lbs./gal. x 60 min./hr. x 20°ΔT = 10,000 BTU's/hour

    Two btu per sq ft for degree difference for a slab
  • HomerJSmith
    HomerJSmith Member Posts: 2,640
    Taco makes a single zone relay panel, I just installed one.
  • Alan (California Radiant) Forbes
    Alan (California Radiant) Forbes Member Posts: 4,394
    Taco makes a single zone relay panel, I just installed one.
    They make a SR501 single-zone pump relay, but I've never seen one for zone valves.
    You could modify the pump relay to operate the zone valve, though.
    8.33 lbs./gal. x 60 min./hr. x 20°ΔT = 10,000 BTU's/hour

    Two btu per sq ft for degree difference for a slab
  • TAG
    TAG Member Posts: 788
    edited December 2020
    First -- I have the three (3) pumps connected to the Viessmann boiler (boiler/DHW/ System) -- does the boiler have an additional 110 output on one of the boards that I should be using for add on 110v items -- like the zone damper transformers ? That would switch off in the summer ?

    Taco makes a single zone "switching relay" ( yes Alan the SR501) and they list zone valves in the description. I'm using some simple Danfoss thermostats in some locations .... But, for 4 locations including this one I'm using a version of the Honeywell T6 Pro that has a floor sensor included with it. It looks the the Taco would give me the 24v out and power to the zone damper.

    I was afraid to power the zone damper direct through T6. The other three manifolds are made by Cross and they have a controller with direct connections for the thermostats .. that's why I went with the Cross vs all the individual heads . But this 4th manifold is only one room so the whole thing is off or on

    The thermostat is just going to be used as a high limit to turn the floor off.

  • HomerJSmith
    HomerJSmith Member Posts: 2,640
    Alan, yes, it was a SR501. I think we need some clarity, here. I missing what he wants to be done.
  • TAG
    TAG Member Posts: 788
    just trying to understand the normal way to connect a zone valve to a thermostat ... can the thermostat control the valve directly just using a 24v power source?

    Is there a reason / benefit using a switching relay?

    There will be transformers for other manifolds ..not sure how much power a zone valve needs. If not much maybe I can just use one there and double it up to run the valve.

    The system seems to be working as planed -- so the thermostat is going to be a high limit to close the valve should the space get to hot

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