Welcome! Here are the website rules, as well as some tips for using this forum.
Need to contact us? Visit https://heatinghelp.com/contact-us/.
Click here to Find a Contractor in your area.

Herman Nielsen Invisible Radiators ~1930

jlt83 Member Posts: 9
Does anyone know of any potential sources for parts for the radiators housing / vents. I have a house full of these radiators with broken damper gears / control knobs and some missing the entire radiator “face”.


  • Steamhead
    Steamhead Member Posts: 16,736
    Herman Nelson was merged into Amercan Air Filter some decades ago. These units have been out of production at least that long. You'd probably have to have something custom-made.

    Post some pics if you can.
    All Steamed Up, Inc.
    Towson, MD, USA
    Steam, Vapor & Hot-Water Heating Specialists
    Oil & Gas Burner Service
  • jlt83
    jlt83 Member Posts: 9

    The mechanism I'm trying to repair is the screw and gear assembly pictured.
  • Jamie Hall
    Jamie Hall Member Posts: 22,962
    The teeth look OK, and the engagement... what is it they aren't doing, or needs repair?
    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England
  • hot_rod
    hot_rod Member Posts: 21,882
    A good machine shop can replicate most any part. 3D printers can do amazing replication also in most any material.
    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream