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Thrush Air Eliminator


I'm trying to figure out how the 4EE Thrush Air Eliminator tank works. It's on the feed side of a hydronic baseboard system from the 1970's. I see the 1/8" nipple and air vent off the top portion of the tank, but I would like to see the inside of it. Does anyone have a cutaway picture to share?



  • Ironman
    Ironman Member Posts: 7,379
    The Extrol tank should NOT be used in conjunction with the Thrush tank.

    It's a simple device that has baffles that cause entrained air to collect and rise to the top as supply water flows through it. It operates on the same principle as a modern MBR.
    Bob Boan
    You can choose to do what you want, but you cannot choose the consequences.
  • billtheplmbr3845
    billtheplmbr3845 Member Posts: 41
    Curios why not to use the expansion tank, does the thrush one work on the same principle as the old fashioned large tanks? I did not notice a drain on the tank to drain it down. Just wondering, never seen one before.
  • SchulerService
    SchulerService Member Posts: 2
    The steel expansion tank is still in the ceiling and was disconnected by another contractor. Does the Extrol tank affect the Thrush and it's ability to work properly?
  • kcopp
    kcopp Member Posts: 4,443
    Can we get more pix of the system ...further back? I am presuming it is a big area in the pipe run that slows down the water flow. The air rises to the top of the tank and is taken out. I think at 1st look it was a conventional expansion tank.