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Tekmar 557 Airgroup operation

Options

Migrated the bulk of my hydronic system controls to (3) Tekmar 552 stats, (1) Tekmar 557 stat, 1 Tekmar 313 wiring center. Bought so we could have the Air Group master prevent the 552s from calling for heat during cooling. 557 serves as cooling stat for entire ground floor HV cooling system. The very rudimentary Uponor heat only stats had NO setback or scheduling capabilities, and could not be over ridden by a master cooling thermostat.

The 552s call for heat when appropriate, but the 557 will not call for heat or energize thermal motor valves through the 313. It will not even allow thermal motor valves as an option, while the 552s will.

Is there some set of dependencies on the 557 since it is an air group master?

Initially reached out to Tekmar: they recommended the system I purchased.Now my follow-up questions seem to be met with “here’s where you can get training” .I am pretty disappointed by this (I work customer service and am repair supervisor for a large test equipment manufacturer).

Any knowledgeable folks, please respond, ask questions, and, as always, on The Wall, thank you!

Comments

  • EdTheHeaterMan
    EdTheHeaterMan Posts: 12,937

    I don't see how the 313 can operate any cooling system. So I guess that you want the 557 to do that and to also operate one of the heating zones thru the 313. Let me dive into this for a minute to see if that is possible.

    Edward Young Retired

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

  • EdTheHeaterMan
    EdTheHeaterMan Posts: 12,937

    Tekmar has always designed its literature to be a little elusive when it comes to proper wiring. They do that so you'll need to take their classes!

    Once you understand the concept behind one wiring design, you can easily adapt that knowledge to just about every other control they make.

    Looking at the 557

    Screenshot 2026-11-10 at 9.33.23 PM.png

    There are two terminals marked Tn2. This is the communication protocol you'll need for the 313.

    Give me another minute to look this over.

    In the meantime, could you take a photo of the wires as you currently have them connected to both the 557 and the 313?

    Edward Young Retired

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