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Uponor Thermal Sealed Actuators: 2 wire vs 4 wire

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cloudd
cloudd Member Posts: 58
in Radiant Heating
Uponor
Stainless-steel Manifold Assembly, 1" with flow meter, B&I, ball valve, 12 loops
PART NO.A2701202

In a new install, why would I pick a 4 wire over a 2 wire thermal sealed actuator? What would determine this?

Comments

  • hot_rod
    hot_rod Member Posts: 27,492
    4 wire means it has an end switch to trigger the boiler or a pump. If you have multiple thermostats you probably want 4 wire.
    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream
  • chippy2
    chippy2 Member Posts: 21

    wouldn’t the controller manage turning on the pumps and boiler?

  • 109A_5
    109A_5 Member Posts: 4,063

    The End Switch verifies the actuators did what they were commanded to do before the pumps are turned on. Your controller part number ?

    image.png
    National - U.S. Gas Boiler 45+ Years Old
    Steam 300 SQ. FT. - EDR 347
    One Pipe System
  • Kaos
    Kaos Member Posts: 879

    With modcons and AWHP where you are running constant circulation, you can use 2 wire actuators. There you don't need anything to trigger the boiler as it is always running.

  • AlaskaDick
    AlaskaDick Member Posts: 38

    As has been described in other posts, a delta P circulator is well suited for use with the 2 wire actuators. Flow in the system will be continuous, but the volume will vary with demand. A modcon boiler can be configured so that it cycles on and off and varies its output to match the load as the actuators open and close and the heating load varies.

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