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wiring in a taco zone valve to a taco switch relay

fronkie
fronkie Member Posts: 7
edited December 2020 in Thermostats and Controls
I recently bought a taco Taco tz075T2-3 zone sentry http://www.taco-hvac.com/uploads/FileLibrary/102-410.pdf , and would like to wire it into a SR502-2 switch relay. http://www.taco-hvac.com/uploads/FileLibrary/SR502(102-082).pdf I have viewed many videos and all of them are not my configuration. Meaning I don't have the four port zone connections. As always TIA for the help.

Comments

  • The Taco SR controls are for pumps. The ZVC controls are for zone valves.

    https://s3.amazonaws.com/s3.supplyhouse.com/product_files/Taco-ZVC403-4- Install.pdf

    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
    fronkieSTEVEusaPA
  • fronkie
    fronkie Member Posts: 7
    Thanks, Now I am even more confused. From this site it states it can be done. https://inspectapedia.com/heat/Zone_Valve_Wiring.php

    Normally one thermostat controls one heating zone and is connected to one zone valve. But as the thermostat is basically an on-off switch, indeed we've discussed with readers the successful combining of more than one zone valve switched by the same thermostat.

    Watch out: to avoid overloading the tt or its power or circuit, check the zone valve wiring instructions. For switching multiple zone valves with one thermostat you may need to have the thermostat control a switching relay that in turn switches the gang of multiple zones.

    A typical switching relay such as the Taco SR502 - 506 can swit3ch 4 zone valves or more.
  • You should have come here first.

    If you look at the wiring diagram for the pump control, you will see terminals for the individual pumps. For the zone valve control, there are terminals for zone valves.
    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
    STEVEusaPA
  • fronkie
    fronkie Member Posts: 7
    I have had the switch relay hooked up for a good six years. What I am having a problem with, is one zone will creep heat every so often in that zone when there is no call. I want to add a zone valve to end this problem. Why it started doing that is a mystery in itself. I also do not need it to turn on a particular circ. I just need it switchable from the power side.
  • EdTheHeaterMan
    EdTheHeaterMan Member Posts: 7,713
    edited December 2020
    There is a way to operate a zone valve from a SR50? control. use a 120 v. to 24 V. step down transformer. power the transformer from the zone you want on the SR relay, Then power the zone valve from the transformer. You will need a separate transformer for each zone valve. I have done that when I needed to have 2 circulator zones and 3 zone valve zones on a separate circ. The end switch from the zone valves operated the 3rd circ on zone 3 of an SR506 control. Total 5 zones.

    You need a separate transformer for each zone valve. I have a diagram if you need it.
    Edward F Young. Retired HVAC ContractorSpecialized in Residential Oil Burner and Hydronics
  • STEVEusaPA
    STEVEusaPA Member Posts: 6,506
    edited December 2020
    Alan is correct in that you are trying to use a multi-circulator control instead of a multi zone valve control. This site showing it can be done is showing a zone valve control.

    Instead of piping in a zone valve, which may be a disaster with banging, why not just pipe in a flow check, or switch your circulator to one that has a built in flow check? There are even isolation valves (B&G) that have flow checks in them.
    By the way, edit your first post and fix the links. Make sure the parenthesis are not in the link.
    steve
  • EdTheHeaterMan
    EdTheHeaterMan Member Posts: 7,713
    If you are using only zone valves for all the zones, then you should get ZVC controls as mentioned above

    The article you posted is about a special circumstance where you want to power more than one valve from a single thermostat. Is that what you are trying to do? We can help you with that. Need details.

    if not... Return the SR control and purchase the proper ZVC control.
    Edward F Young. Retired HVAC ContractorSpecialized in Residential Oil Burner and Hydronics
  • fronkie
    fronkie Member Posts: 7
    Instead of piping in a zone valve, which may be a disaster with banging, why not just pipe in a flow check, or switch your circulator to one that has a built in flow check? There are even isolation valves (B&G) that have flow checks in them.

    Cannot add a flo check b/c the heated water is flowing correctly, such the need for the zone valve.
  • fronkie
    fronkie Member Posts: 7

    If you are using only zone valves for all the zones, then you should get ZVC controls as mentioned above

    The article you posted is about a special circumstance where you want to power more than one valve from a single thermostat. Is that what you are trying to do? We can help you with that. Need details.

    if not... Return the SR control and purchase the proper ZVC control.

    As I've stated above.
    I have had the switch relay hooked up for a good six years. What I am having a problem with, is one zone will creep heat every so often in that zone when there is no call. I want to add a zone valve to end this problem. Why it started doing that is a mystery in itself. I also do not need it to turn on a particular circ. I just need it switchable from the power side.


  • EdTheHeaterMan
    EdTheHeaterMan Member Posts: 7,713
    edited December 2020
    The flow check is the correct way to solve your problem. There should already be Flow Check valves there anyway, but you may need 2. Here is a publication with your situation http://media.blueridgecompany.com/documents/ZoningMadeEasy.pdf
    Starts on page 11 and finished with a diagram on page 12
    Edward F Young. Retired HVAC ContractorSpecialized in Residential Oil Burner and Hydronics
  • fronkie
    fronkie Member Posts: 7

    The flow check is the correct way to solve your problem. There should already be Flow Check valves there anyway, but you may need 2. Here is a publication with your situation http://media.blueridgecompany.com/documents/ZoningMadeEasy.pdf
    Starts on page 11 and finished with a diagram on page 12

    Thank you Ed, This could be the ticket. So the question is; why do I need two more, as this was never a problem in the past?
    Unruly air pocket?
  • Yes, that is strange that it would have started out of the blue, but it's not the first time I've heard that. It's called ghost flow (or phantom flow or gravity flow).

    We use it to our advantage when we bring a return line back to the water heater for a DHW circulating system. The piping is sloped back down to the water heater and hot water will circulate.

    Use a good quality check valve; make sure it has a soft seat, otherwise it will chatter. Caleffi makes a great one.
    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
    fronkie
  • EdTheHeaterMan
    EdTheHeaterMan Member Posts: 7,713
    edited December 2020
    If you still want to do the zone valve on just that zone, you can put the circulator and the transformer on the same 120V contacts for that zone. the valve will open and the circ will operate at the same time.


    The problem is... If the valve fails to open, the circ will "deadhead". That means it will operate without moving any water ...and that's not good.
    Edward F Young. Retired HVAC ContractorSpecialized in Residential Oil Burner and Hydronics
    fronkie
  • EdTheHeaterMan
    EdTheHeaterMan Member Posts: 7,713
    edited December 2020
    The end switch is not rated for 120 volts. but if you have an extra unused zone on your SR control you can use the end switch to power the extra zone. The extra zone can power the pump for that zone.

    In this illustration, zone 5 is operated by the room thermostat and zone 1 is operated by the zone valve end switch. If the valve fails then the zone valve will not send the signal for the circulator to operate.


    In this Illustration, zone 5 and zone 1 on the SR 506 control is the same zone. operated by the thermostat connected to zone 5


    Edward F Young. Retired HVAC ContractorSpecialized in Residential Oil Burner and Hydronics
  • EdTheHeaterMan
    EdTheHeaterMan Member Posts: 7,713
    edited December 2020
    fronkie said:

    The flow check is the correct way to solve your problem. There should already be Flow Check valves there anyway, but you may need 2. Here is a publication with your situation http://media.blueridgecompany.com/documents/ZoningMadeEasy.pdf
    Starts on page 11 and finished with a diagram on page 12

    Thank you Ed, This could be the ticket. So the question is; why do I need two more, as this was never a problem in the past?
    Unruly air pocket?
    You have a check valve already in the system somewhere. Otherwise when other circulators operate they will force water backward in the remaining loops that are not calling for heat. (that is explained in the text you just read)

    Perhapse the check valve on that loop has failed. Are your checks part of the circulator pump? It would say IFC on the pump in the model number or "includes internal flo check" on the label.

    Have you replaced a circulator recently?
    Edward F Young. Retired HVAC ContractorSpecialized in Residential Oil Burner and Hydronics
    fronkie
  • fronkie
    fronkie Member Posts: 7
    edited December 2020
    Thank you gentlemen! Excellent info on all accounts.
    I have not replaced any circs recently, infact never.
    2 Backflows/check valves are installed, and yes I did replace the one, thinking it was bad.
    Caleffi it is.
    Ed, I do like the simplicity of the first schematic.
    If I missed anything, forgive me.
    Regards,
    Frank