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Thrush valve maintenance?

nicholas bonham-carter
nicholas bonham-carter Member Posts: 8,576
edited February 2021 in THE MAIN WALL
About to do the yearly draining of the compression tank.
Is there anything needed on the Thrush valve?—NBC

Comments

  • WMno57
    WMno57 Member Posts: 1,250
    This Thrush valve?

    https://heatinghelp.com/assets/documents/221.pdf

    My system has an additional isolation valve between the Thrush valve and the compression tank. I'm not sure the isolation valve is needed.

    Reason I say that is I recently had my compression tank replaced (pinhole leak) with a like compression tank. This was done with a full wet system, and the thrush valve held back the water.




    I DIY.
  • JUGHNE
    JUGHNE Member Posts: 11,042
    WM, did you have a isolation valve on the return line at the pump?
    It seems you would have to stop the water from draining out that way.
  • WMno57
    WMno57 Member Posts: 1,250
    This is on the return, but the flippers are stuck, so it hasn't changed in years.


    No isolation valves by the pump either.


    Maybe a partial vacuum in a second floor radiator held the water back?
    I DIY.
  • mattmia2
    mattmia2 Member Posts: 9,576
    So it is just a flow check with an air scoop on top of it?
  • Big Ed_4
    Big Ed_4 Member Posts: 2,762
    edited February 2021
    Thrush made the best valves , as you can see they last forever ... I never had to clean one ...
    I have enough experience to know , that I dont know it all
  • WMno57
    WMno57 Member Posts: 1,250
    mattmia2 said:

    So it is just a flow check with an air scoop on top of it?

    I guess so. It works great. I went two entire heating seasons without draining the compression tank. No Airtrol on the tank either.
    I DIY.
  • Big Ed_4
    Big Ed_4 Member Posts: 2,762
    Not exactly an air scoop but the tap for the expansion tank is just below the check flap . Any air that migrates down and collects as a bubble would rise back up into the tank ..
    I have enough experience to know , that I dont know it all