We were talking about early heating systems, Ara and I. I had questions and he had answers. When you want to know stuff about how things began, it pays to ask someone who has been dead for a while. Guys like that were there at the start and saw most of it for themselves.
U.S. Consumer Product Safety Commission, along with boiler manufacturers U.S. Boiler Co., New Yorker Boiler Co. and Crown Boiler Co., announced voluntary recalls of boiler models due to carbon monoxide poisoning hazards.
North American hydronic professionals can now choose from dozens of modulating/condensing (mod/con) boilers. Many are designed for wall-mounting. Those who design these boilers strive for small enclosures and low weight.