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Zone valves on a Switching Relay

My Argo 3 zone switching relay died and I replaced it with a Taco just to get it up and running. After doing some digging, I realize that I might have an unconventional setup (I think). I have 5 zones (5 thermostats), a 3 zone switching relay (Taco), 3 circulator pumps, and 3 zone valves. I know normally you're supposed to get a ZVC with zone valves, so I'm not sure why the contractor went this route. Maybe someone can shed some light.

2 of those zone valves must be being powered by a transformer somewhere but not sure exactly where. 1 zone valve is being powered by the 24VAC output terminal on the switching relay. I'm wondering if I can power the 3rd zone valve from the air handler transformer itself (same one that is powering the thermostat), and rewire it so I can use the output on the 24v terminal to an outdoor reset.

Thanks for any input.

Comments

  • HomerJSmith
    HomerJSmith Member Posts: 1,815
    edited September 26
    How can you have 5 thermostats with 3 pumps and 3 zone valves, that makes 6. Unless two are running off of one thermostat? I guess I'm missing something.
  • BigEHead
    BigEHead Member Posts: 26
    Sorry I included the primary pump on the boiler.  I have 2 other pumps and 3 valves for 5 zones.
  • BigEHead
    BigEHead Member Posts: 26
    Is it normal to see zone valves connected to switch relays, or 5 zones connected to a 3 zone panel?
  • hot_rod
    hot_rod Member Posts: 17,531
    If the zone valves are 120VAC they could connect to a switching relay. No end switch however

    you can mix and match valve and pump relay boxes

    Typically a zone valve needs to trigger on circulator when they open, so at least one pump could connect to the zone valve relay box

    You don’t want to start mixing multiple transformers, it is not easily done, try to wire all of it to two relay boxes 
    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream
  • BigEHead
    BigEHead Member Posts: 26
    thanks Bob. that's what's so bizarre, these are 24v honeywell 4 wire zone valves. since they are 24v, i'm assuming 2 of the 3 are powered by the same transformer that is powering the thermostats (the ones in the air handlers). the 3rd one is being powered by the 24v output terminal on the switch relay.

    is it possible to move the 3rd zone valve onto it's respective air handler transformer?
  • EdTheHeaterMan
    EdTheHeaterMan Member Posts: 4,271
    edited September 28

    How can you have 5 thermostats with 3 pumps and 3 zone valves, that makes 6. Unless two are running off of one thermostat? I guess I'm missing something.

    Easy. 2 pump are powered by thermostats
    one pump is powered by any one of the three zone valves.

    Zone valves don't move water... they just stop it from moving... pumps move water!

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

  • EdTheHeaterMan
    EdTheHeaterMan Member Posts: 4,271
    edited September 28
    BigEHead said:

    Is it normal to see zone valves connected to switch relays, or 5 zones connected to a 3 zone panel?

    There is no "Normal" for your system when comparing to the world of possibilities. Your system is unique to your home/building. If I wanted to have 10 zones on one pump (back in the day before ECM pumps) I would be hard pressed to find a pump that could properly handle 30 GPM if all zones were open and 3 GPM if only one zone was open. But the B&G 100 series could do that with 15 GPM and 3 GPM with only a small change in head pressure. So I might decide to split the 10 zone valves into 2 sets of 5 zone valves, operated by a separate pump for each of the 5 zones. See the explanation on page 17 of this booklet. http://media.blueridgecompany.com/documents/ZoningMadeEasy.pdf.

    There is a lot of basic information in this booklet. Easy to read and easy to understand.
    Edward Young
    Retired HVAC Contractor from So. Jersey.
    Services first oil burner at age 16
    P/T trainer for EH-CC.org

    BigEHead
  • EdTheHeaterMan
    EdTheHeaterMan Member Posts: 4,271
    hot_rod said:

    If the zone valves are 120VAC they could connect to a switching relay. No end switch however

    you can mix and match valve and pump relay boxes

    Typically a zone valve needs to trigger on circulator when they open, so at least one pump could connect to the zone valve relay box

    You don’t want to start mixing multiple transformers, it is not easily done, try to wire all of it to two relay boxes 

    @109A_5 might get his SHORTS crossed
    Edward Young
    Retired HVAC Contractor from So. Jersey.
    Services first oil burner at age 16
    P/T trainer for EH-CC.org

  • BigEHead
    BigEHead Member Posts: 26
    edited September 28
    Thanks all. Primary pump off the boiler pumps to all zones - 3 of these zones are controlled via zone valves. The other two zones are connected to their own pumps.

    I'm not sure how the 2 zone valves are powered - but i know the 3rd is powered via the 24v output terminal on the switching relay. Would it be ok to remove it from there, and power it up directly from the air handler via the thermostats? I believe that's how the other 2 are connected. Thanks again.