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Connection from Taco SR501 to RINNAI I-Series combi boiler

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MountainView
MountainView Member Posts: 3
in Thermostats and Controls

I understand the I-series boiler has a switch relay internally for single zone. I have already set up a switch relay and grundfos pump powered separately from my boiler. I have a tekmar smart thermostat already connected to the switch relay. I need to know how to connect my switch relay to the combi boiler. I am thinking the T/T 1 Connection at the boiler to the C and N/O connection at relay but the t/t conn has the three connections C, R and W. Is there a different place in this panel I should connect for call for heat when pump kicks on?

image.jpg image.jpg

Comments

  • Jamie Hall
    Jamie Hall Member Posts: 27,415

    Use R and W on the boiler. C is provided for a common return from powered thermostats.

    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England
  • MountainView
    MountainView Member Posts: 3

    ok. So c and w on boiler to the n/o and c on relay?

  • EdTheHeaterMan
    EdTheHeaterMan Member Posts: 12,319
    edited 3:26PM
    https://forum.heatinghelp.com/discussion/comment/1895060#Comment_1895060

    R and W will run the boiler. R and W. = Will Run

    image.png

    In this illustration I have fadded out the unimportant parts of your photo and highlighted the important parts of the diagram. Take 5 (COM) from the Taco SR501 and connect it on R for zone 1 of the Rinnai I-Series. Take 6 NO from the Taco SR501 and connect it to W on the Rannai I-Series as shown above.

    Edward Young Retired

    After you make that expensive repair and you still have the same problem, What will you check next?

  • 109A_5
    109A_5 Member Posts: 4,104
    edited 3:18PM

    The common and the N/O on the relay really don't matter which go to the R or W on the control board. The ''C" on the control board is not used.

    image.png
    National - U.S. Gas Boiler 45+ Years Old
    Steam 300 SQ. FT. - EDR 347
    One Pipe System
  • 109A_5
    109A_5 Member Posts: 4,104

    It just acts like a switch, closed calls for heat, open no call for heat.

    National - U.S. Gas Boiler 45+ Years Old
    Steam 300 SQ. FT. - EDR 347
    One Pipe System
  • MountainView
    MountainView Member Posts: 3

    Thanks everyone for the direction.

  • 109A_5
    109A_5 Member Posts: 4,104
    image.png
    National - U.S. Gas Boiler 45+ Years Old
    Steam 300 SQ. FT. - EDR 347
    One Pipe System

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