This was found in a crawl space of our museum.
House is at 100 years old, was a residence, then a hospital, then nursing home and now local museum.
This is a "Sands 50" gas fired heater.
22" tall, 7 1/2" around.
Nameplate was lost.
Has two 3/4" OD double spiral copper tubes inside.
1"inlet-- 3/4" outlet-- 3" flue--baffle inside exhaust.
Interesting Swastika trademark on the gas stop, leads me to believe pre WW2 era.
Installed gas orifice is # 58---12,300 on LPG.....more on butane? or manf gas.
Two extra orifices hanging on wire are #46 and #29.
NG was not available until 1966 so it was not using that. No NG ever to house.
Could it have been butane as that is not much fire on LPG?
To use just make sure it had water maybe running? Put your kitchen match to the burner and turn on the gas!
But like many tankless....parts are hard to find.