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Old Wirsbo adjustment

paako Member Posts: 2
I understand that the unit holds the rod of valve down until heat is called. Then the motor goes up letting water flow to the lines. I   know the actuators has a indicator. But if the acguator is turned all the way down went heat us called will it raise. Or do you have a rule of thump on this adjustment.


  • Dave Carpentier
    Dave Carpentier Member Posts: 587
    The little dot should align with the arrow. As you screw the actuator tighter or looser the arrow moves around. Just align the arrow to the dot. This allows the mechanism inside the MVA to travel within it's range for opening and closing. Internally, if I recall, the metal part internally that goes up and down is strong, but it's attached to the body inside the MVA with plastic parts that are not too strong.

    If you want the valve open all the time, just remove the MVA from the valve.
    If you want the valve closed all the time, align the MVA arrow/indicator and cut one of the yellow wires to it.

    ps : Try to keep your Wirsbo MVA messages in the same thread and just add a reply to it.
    It makes the flow of messages on this board much easier to read.

    (maybe the mods will merge these 2 threads ?)
    30+ yrs in telecom outside plant.
    Currently in building maintenance.
    tim smith
  • Big Ed_4
    Big Ed_4 Member Posts: 2,785
    The spring loaded plunger up open down closed .
    I have enough experience to know , that I dont know it all