The return trap is like a mechanical condensate pump. This 1943 piece about Sarco Alternating Receivers and Lift Traps from the Sarco Company does a nice job of explaining how it works.
This booklet from 1905 showcases how American Radiator Company's radiators could become decorative pieces in a home. It highlights the "beauty in modern radiators" of tha...
American Radiator Company manufactured their Colonial Wall Radiators around 1905. The document attached below is an excerpt from The Ideal Fitter (1905) that states "The ...
Here are photos of a circa-1944 Perfex Series 155 Magic Dial Thermostat, as well as the instruction manual.