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how to replace actuator on wisbro manifold ?

I got two bathrooms with radiant heat supplied by a 10-year old Wisbro manifold. One bath is getting some heat, the other is getting none. Since there's hot water to the manifold, my best guess is that the actuators are the problem.

I've gotten the uponor A3023522 thermal actuator, which seems to be the successor model to the existing actuators. I've also gotten a VA33 to connect to the brass manifold.

How do I actually replace the actuators ? Do I need to drain the loop ? Also, the actuators are on the bottom of the manifold, the return lines on the top. All the literature I've seen has the actuator on the top. Does this matter ?

thanks,
sean

Comments

  • Zman
    Zman Member Posts: 7,330
    edited December 2016
    The valves should just unscrew from the base. No water to worry about.
    The wiring should be the same as the old one.
    Upside down should not effect operation.
    "If you can't explain it simply, you don't understand it well enough"
    Albert Einstein
    seandarcy
  • rick in Alaska
    rick in Alaska Member Posts: 1,362
    Depends if the thermal actuator is bad, or the operating stem under it. If you watch the operation of the actuator when it is open, it should have a color band sticking up above it. Usually takes 2-3 minutes to get to that point. The best way I know of to check the stem is to take the actuator off by squeezing around the base and pulling it off, then checking the stem by pushing down on the plunger. The plunger should move up and down freely. If you have to change out the stem, you will need to close down any valves feeding the manifold. Then just unscrew the stem and put in a new one.
    Rick
    seandarcy
  • Mark Eatherton
    Mark Eatherton Member Posts: 5,839
    They want the operator on top of the manifold to avoid the possibility of water leaking directly into the ZV motor. If you have no leaks, it shouldn't be a problem.

    ME
    It's not so much a case of "You got what you paid for", as it is a matter of "You DIDN'T get what you DIDN'T pay for, and you're NOT going to get what you thought you were in the way of comfort". Borrowed from Heatboy.
    seandarcySWEI
  • seandarcy
    seandarcy Member Posts: 21
    Thanks for all your quick responses.

    And now, the uponor instruction sheet says :

    Thehe actuator is shipped locked partially open. To unlock, apply power for a minimum of six minutes. Failure to do so will allow flow through the loops.

    So if I don't apply power, I'll get flow regardless of the thermostat ? And what does apply power mean ? Just hook up the four wires ?
  • Dave H_2
    Dave H_2 Member Posts: 503
    After you hook up the wires, turn the heat up in those rooms. This will energize the actuators. Leave on for at least 10 minutes, then you can turn the thermostat setting back down to your desired level.

    Now there have been several styles of actuators over the years so there are different mounting options. Can you send a pic along of your existing actuators on the manifold?

    Dave H.
    Dave H
  • hot_rod
    hot_rod Member Posts: 16,286
    Check the stem when you replace actuators.
    First for any signs of leak or seeping around the o-rings.

    Also that the stem can be pushed in easily. Once they start to seize up, they can destroy the actuators.

    My rule of thumb is to use my thumb nail and push the stem.

    If it puts a hole through the your nail and doesn't open, replace the stem assembly :)

    Agree with Dave, the various vintages of actuators do not always interchange, even if the thread is the same. It has to do with the pin stroke dimension.





    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream
  • seandarcy
    seandarcy Member Posts: 21
    Yes, I do need to place the manifold valves themselves. In the image the valve on the left was never used. The other two had actuators attached. Those two have stems that haven't seized, but are more difficult to move.



    I'm thinking of using this valve:

    http://www.supplyhouse.com/Wirsbo-Uponor-A2620017-TruFLOW-Replacement-Manifold-Valve

    I assume I unscrew the existing valve and replace it with the new one. The manifold has no close-off valves. I can close off the supply and the return to the manifold at the boiler. Is that enough to avoid flooding?
  • seandarcy
    seandarcy Member Posts: 21
    The uponor description of the manifold:

    The TruFLOW manifold comes
    with black plastic caps mounted
    on the return manifold for manual
    operation of the on/off valves.

    How would you use the black plastic caps to open the valve ? I thought these where piston valves. That is, when the piston was in the valve was closed. So the actuators closed the valve by pushing on the stem. When the stem was out the valve was open. And how would you adjust the stem using the plastic cap ??
  • hot_rod
    hot_rod Member Posts: 16,286
    when you screw on an electric actuator it pushed the valve closed, when it powers up the piston in the actuator retracts, the pin in the manifold backs out, to allow flow.

    See the stem pic I posted above. As I push the pin in, the valve closes.

    If you remove an actuator the port is full open.

    The plastic cap allows you to push the pin down and close off the port, just as the actuator does when not powered.

    The center of the three in your picture appears to have an adapter ring for the actuator to mount on.
    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream
  • Dave H_2
    Dave H_2 Member Posts: 503
    If you have actuators on the manifolds, the black plastic caps have been removed. It is a two-piece design threading onto the manifold then turning the cap to open and close the valve.

    Dave H.
    Dave H
  • seandarcy
    seandarcy Member Posts: 21
    Supply House says:

    Unfortunately the SKU: A2620017 you selected does not work for the older brass Wirsbo manifold. The is for the newer Uponor tru-flow manifolds. All parts for the older Wirsbo manifold are obsolete. If you wish to replace the valves you will need to replace the entire manifold at this time.

    So I've got to replace the entire manifold. Definitely not DIY !