Cast Iron Vs Steel Hot Water Boilers

DaveGateway

usualy use steel on their low end vertical tube economy models. Cast iron has always been thought to have better heat retension, but Viessmann uses both steel and CI on their top of the line Vitola. Large commercial boilers have been steel for years. I'd assume the weight and cost of cast iron makes it impractical on very large boilers. The boiler design plays more into the efficency of the boiler. Vertical tube steel boilers have higher standby loss then a 3 pass cast iron boiler. The counter flow design of the Laars Max steel boiler mimics a 3 pass CI design with less weight and equal efficency ratings. I guess the use of cheaper thin guage steel vertical tube boilers have given them a "poor quality" view in the industry. Old cast iron boilers have been know to last over 50 years when taken care of so does that make them better? Bottom line: the top efficency oil fired boilers are all 3 pass CI designs.

John MacGregor

Cast Iron Vs Steel Hot Water Boilers

Which is considered a better choice for a residential boiler. Cast iron or steel?