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Question re: TN4 from Tekmar

... from what I can tell, the TN4 system consists of a 2-wire bus for communication purposes and 24VAC relays for actuators / interfacing with extant building control accessories such as manifold actuators. Here is my question:

From what I can tell but I'd like to confirm: is it possible to place multiple TN4 thermostats on the same bus on a zone manager such as the 337? I ask, since I am considering splitting zone in my house, which would entail putting 24VAC actuators on the existing RFH manifolds. Ideally, the zone manager would be smart enough to turn on the valve to the manifold, whether it's one or both thermostats are calling for heat. The thermostats in turn would control the actuators.


  • singh
    singh Member Posts: 866

    I don't think that would be possible, with the Tn4 control system.
    You may need to get a 335 to expand the zones the way you want.

    Of course give Tekmar a call to confirm.


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  • Constantin
    Constantin Member Posts: 3,796
    Here is what I meant...

    I sent a message to the local Tekmar representative, but have yet to hear back... anyone else I can contact?
  • Constantin
    Constantin Member Posts: 3,796
    And for what it's worth...

    I got word back from FIA (the local representatives) that this is possible. Thus, the TN4 system shapes up to be REALLY interesting for folk who have limited bus wires but who'd like to microzone an existing installation. One 337, and a bunch of thermostats, and some zone valves would allow me to microzone my house. Nifty!
  • Randy Baerg
    Randy Baerg Member Posts: 26
    tekmar tN4

    For the tekmar tN4 Network you can connect up to 24 devices (thermostats) per communication Bus. In a thermostat only network there is one Bus, so 24 is the limit. If adding a tN4 'system control' you can generate up to four Buses which means up to 96 thermostats operating on the network.The 337 Zone Manager provides connection for 6 thermostats and zone valves and Two zone group pumps.These could be split into two Buses with a system control. If you only need one Bus and one zone group pump(no system control giving 2 Buses)then I would use the 335 for 6 zones / 1 group pump (less $).
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