Age of American Standard boiler G404 Series 4BJ3

This is running steam. Homeowners said system has been running great and fuel bills are reasonable. The low water cut off needed work and the contractor broke the brass gage glass fitting in the casting. The system was overfilled, but owner said there was no water coming from the box…only the low water cut off. They had been told boiler was from 1987…I didn't think so. I figured 1950's early 1960's. I had the 3 foot tall American Standard gray/silver sheetmetal atmospheric in my old home that post dated these models, IIRC. This has the brown sheet metal cover. Mine was the one that looked a lot like the Burnham Independence, with two 2 inch supplies on top…also built like a tank. I always got really nice combustion numbers on the gray covered model…20 to 30% excess air, with analyzer efficency around 78%. Those older cast iron burner atmospherics always seem to have much better combustion efficiency than the newer steel tube burners that run about 50% excess air.

Good catch