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Help with wiring issue

I have a taco sr504-4 circulator switching relay with a primary secondary loop. Off of secondary loop I have a circulator (120v) and I have 6 taco zone valves with 6 thermostats. Is there a way without adding a zone valve switching relay to power up the circulator when a zone valve endswitch makes. I have an indirect water heater and radiant heat in basement floor. Walked into this nightmare and any help would be appreciated.


  • Paul48
    Paul48 Member Posts: 4,469
    Put the zvc 406 in, otherwise you're just continuing the "cobbling".
  • Ironman
    Ironman Member Posts: 7,085
    edited October 2015
    I concur that the zvc 406 is the way to go, but not the only option available.
    You could tie all of the end switches together in PARALLEL and connect them to the "TT", " RW" terminals on one of the zones of the sr504. Connect the pump to that same zone. Then, connect the indirect and its circ to the priority zone in the sr504. Turn the priority switch to "on". The primary pump should be connected to the boiler's control to run when the boiler is called from any zone. A somewhat " cobbed" method, but it will work. This is how we had to do it before the ZVC panel came along.
    You didn't specify what type of boiler, so I assumed an atmospheric. If the boiler has provision for domestic priority, then the indirect should be connected directly to it, unless it's piped as a secondary loop.
    Bob Boan
    You can choose to do what you want, but you cannot choose the consequences.
  • Joe Mattiello
    Joe Mattiello Member Posts: 654
    You should have enough capacity with the sr504 providing some if not all zone valves energize 1 of the 4 pumps on relay. Parallel ends witches on zone valves to corresponding pumps. Reserve 4th zone for DHW zone for optional priority. Call me Monday at Taco if you have additional questions
    Joe Mattiello
    N. E. Regional Manger, Commercial Products
    Taco Comfort Solutions
  • vosac
    vosac Member Posts: 3
    edited October 2015
    easy solution is make a jumper bridge the black wire (go to the circ pump )from 1 zone to another. Remove the relay switch on the bridge zone or remove thermostate wire connect to that zone. When the first zone call for heat the bridge zone will also have 120v out going to the circ pump. i am not sure if that is the legal way to do it.