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Constant circulation-Wiring/control strategy

STEVEusaPASTEVEusaPA Posts: 2,015Member
edited July 2016 in THE MAIN WALL
Hello forum. I wanted to continue a conversation from another thread based on this idea for constant circulation:
http://www.pmmag.com/articles/88410-zoning-with-constant-circulation-br-john-siegenthaler

I am ok with the wiring for the Indirect, boiler demand (via a sensor in the buffer tank), and injection mixing.

But I can't figure out how I would control the zones, with the attached piping diagram, meeting the following goals:

Constant circulation on the 6 zones, with power to the circulators disrupted when the boiler control (Tekmar 374) is in WWSD. A few ideas are:
a) Have the thermostats connected to a zone control panel, connected to boiler control, only operating the 3-way zone valves. Separate zone panel control, t-t's jumped, supplying power to the circulators. Just cant figure out how to break power to the circs during WWSD.
b) With Caleffi's 6443..3BY - 3-way By-pass valve it appears I can wire to do this. Although the instructions say the valve should be on the supply, and Siggy had it on the return (maybe a different valve).

I can't tell from Tekmar (emailed support), or any of the other companies zone panels, how WWSD would turn off the circulators.

This is on an existing oil-fired system (my house). I've piped this a few different ways as an experiment and to satisfy my own curiosity. I think this will be the final time, because for one, I'm getting too old, and 2, my wife feels I have an unhealthy attachment to hydronics...lol

Anyway, here's the piping diagram (sorry so crude). Just the major components are on there. I didn't feel like drawing in all the isolation valves.

Any thoughts/comments/suggestions would be greatly appreciated.
Thanks Wallies
Steve



steve

Comments

  • Paul SPaul S Posts: 1,257Member
    edited July 2016
    i use these sometimes....its just a break on temp rise control ..you can break the incoming line voltage to the pump control....set it to the same temp for the wwsd on the tekmar...i believe the sensing bulb has a capillary about 8 to 10 ft long ....run it to the same location near the tekmar outdoor sensor....i tuck them under the siding if that's what you have..
    ASM Mechanical Company
    Located in Staten Island NY
    Servicing all 5 boroughs of NYC.
    347-692-4777
    [email protected]
    ASMHVACNYC.COM
    https://heatinghelp.com/find-a-contractor/detail/asm-mechanical-company
  • STEVEusaPASTEVEusaPA Posts: 2,015Member
    edited July 2016
    That's a good idea Paul. My only concern is I wonder if both outdoor sensors, even side by side would register exactly the same, but I could make your secondary sensor 1 degree different. I guess I could Ohm them out and adjust accordingly
    steve
  • Paul SPaul S Posts: 1,257Member
    i have a bunch of these installed side by side ...there pretty accurate....this setup is out of sight otherwise i tuck the sensing bulb under siding....or install ot in a plastic type well for aesthetic reasons
    ASM Mechanical Company
    Located in Staten Island NY
    Servicing all 5 boroughs of NYC.
    347-692-4777
    [email protected]
    ASMHVACNYC.COM
    https://heatinghelp.com/find-a-contractor/detail/asm-mechanical-company
  • hot rodhot rod Posts: 8,041Member
    There are no doubt a few ways to do this. Cody up at our office came up with this.




    Bob "hot rod" Rohr
    trainer for Caleffi NA
    The magic is in hydronics, and hydronics is in me
  • STEVEusaPASTEVEusaPA Posts: 2,015Member
    Thanks Bob for your thoughts. With the ZVR106, in WWSD, would the panel still energize a zone valve if a t-stat was calling?
    steve
  • STEVEusaPASTEVEusaPA Posts: 2,015Member
    @Paul S. Is that the Honeywell T991A?
    steve
  • Paul SPaul S Posts: 1,257Member
    edited July 2016
    yes i believe so....in that drawing above stats will still energize zone valves during wwsd.....i have done both setups honeywell t991 and tekmar setpoint controller, both work fine
    ASM Mechanical Company
    Located in Staten Island NY
    Servicing all 5 boroughs of NYC.
    347-692-4777
    [email protected]
    ASMHVACNYC.COM
    https://heatinghelp.com/find-a-contractor/detail/asm-mechanical-company
  • Paul PolletsPaul Pollets Posts: 3,077Member
    I'm not aware of any mod-con boiler that's set up for constant circulation with the integral boiler computer except the Viessmann Vitodens 200 models. I wonder why that is?
  • SWEISWEI Posts: 7,356Member
    Unless I'm misunderstanding this, TT has always had the option in software. Now without internal feedback...
  • STEVEusaPASTEVEusaPA Posts: 2,015Member
    @hot rod
    Regarding this Caleffi 3-way bypass, a few questions.
    1. It appears from the literature that the valve is powered open and powered closed-not needing constant current to hold it 'open'? Is that correct?
    2. Which way is N.C.? It seems I want the thermostat to rotate it like on the left side when calling for heat, and on the right when satisfied. Is that the way it works/can it be wired to work that way?
    3. It also appears this valve with my piping diagram will only work on the return, yet Caleffi specifies it should be on the supply. Can I put this on the return per my drawing?
    Thanks
    Steve

    steve
  • hot rodhot rod Posts: 8,041Member
    edited July 2016
    Correct, power open, power close, no power consumed when it is at either position.

    Now that valve is a bypass, notice the Cv in the two positions. When it is straight through it is a full port, high 12 Cv. In the other position it has a small passage way, the side of the ball is carved away.

    I think you want a diverting valve, same flow either direction?

    Unless you like the non power consumption and high close off, the Z-one 3 way is maybe a better option. It powers one way, spring return. Up to a 7.5, depending on the model, Cv either direction.

    There is no N.C or N.O. on a three way valve, just flip it over to change which witch is which on the Z-0ne. So basically chose power open or power close by just flipping the body over. Probable go with the spring close in the position it will be in most of the time.

    You can either flow into the AB to either side, or flow out of AB, there is no flow direction requirement either.

    These slides show power consumption of the various valves, the Z-one is .3W all the time it is powered, 0 draw when spring returned.

    The other slide shows how the Cv of the valve, the size of the port, changes the close off pressure.

    If you need a high close off, like a pressure application, chose a lower Cv valve.











    Bob "hot rod" Rohr
    trainer for Caleffi NA
    The magic is in hydronics, and hydronics is in me
  • STEVEusaPASTEVEusaPA Posts: 2,015Member
    Thanks again HR. I think (hope) this is on the same (right) track.
    steve
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