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Connecting Taco SR503-4 Three Zone Switching Relays and Ecobee Thermostats

HeatingHelp
HeatingHelp Administrator Posts: 680
edited November 2021 in THE MAIN WALL
Connecting Taco SR503-4 Three Zone Switching Relays and Ecobee Thermostats

Here are instructions for connecting Taco SR503-4 Three Zone Switching Relays and Ecobee thermostats.

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Comments

  • Dave H_2
    Dave H_2 Member Posts: 587
    Unfortunately, this answer doesn't really answer the original poster's question. If you only have two wires connected to your thermostat that has batteries, you will need a third wire or a "common-maker" as I have seen available to make this work.
    This does help with wiring hi power-stealing stats with switching relays.

    Dave Holdorf

    Technical Training Manager - East

    Taco Comfort Solutions

  • Erin Holohan Haskell
    Erin Holohan Haskell Member, Moderator, Administrator Posts: 2,354
    Thanks, @Dave H_2. Please let me know if you have more resources that we can share here.

    President
    HeatingHelp.com

  • Dave H_2
    Dave H_2 Member Posts: 587
    You are so welcome and thanks for posting this. We get a lot of calls regarding this and I hope this can help.

    Dave Holdorf

    Technical Training Manager - East

    Taco Comfort Solutions

  • sjamz
    sjamz Member Posts: 1
    edited December 2021
    The ecobee instructions are misleading (especially about the 1 amp rating). Taco documentation has been updated to show where to connect common. See page 56 of their wiring guide (https://www.tacocomfort.com/documents/FileLibrary/100-92.pdf). FAQs on the Taco site also address this. (And yes you do need the third wire.)
  • lost11
    lost11 Member Posts: 39
    i think argo really explains it best in their manual (https://argocontrols.com/sites/default/files/240005129 ARGO ARM Series IOM REV E.pdf) all these controllers are NOT designed to work power robbing thermostats without additional power. you need the additional transformer for MORE power than the boards were originally designed for.