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Hydraulic Separator physical placement

Peterug13 Member Posts: 8
edited October 2021 in Gas Heating
I have a limited space install. Currently the plans call for the hydrosep to be mounted lower than the boiler and feed/return manifolds. About 12-14” lower but still lower than both. I’m wondering about the effectiveness of air removal in the HS being below everything. Should I put a second air scoop in the primary loop?  Comments? 


  • Dave H_2
    Dave H_2 Member Posts: 527
    That will depend upon your Hydro-Sep. Alot of them have an air vent installed at the top for convenience of getting the air out of the hydro-sep and that's all. So in essence, yes, I would install an air separator

    If your Hydro-Sep has a collision media inside, then you have an air separator already built in and do not need to add another.

    Being below the boiler is irrelevant because all of the water/air has to pass thru it.

    Dave H.
    Dave H
  • Peterug13
    Peterug13 Member Posts: 8
    edited October 2021
    Thanks Dave. Using a Taco Hydro-Sep. I’m going to include an air sep as well. 
  • JohnNY
    JohnNY Member Posts: 3,200
    I would not include a second air separator after spending the money on a hydraulic separator. I love those things but they are always massive and difficult to place in the system. In fact, where space is an issue, I don't use them at all. But they do a great job of eliminated both air and dirt and I've never made any effort to place one below the boiler and I don't know where that directive comes from.
    Contact John "JohnNY" Cataneo, NYC Master Plumber, Lic 1784
    Plumbing in NYC or in NJ.
    Take his class.