Welcome! Here are the website rules, as well as some tips for using this forum.
preventing corrosion in a gas fired cast iron boiler
I have a Burnham Series 2, M/N 205NI-A2 to heat my home. It's start temperature is set to 140F with an high limit of 180F and differental of 15F (factory settings). What constitutes a "sustained" low boiler water temperature? From a cold start the boiler temperature reading recovers to above 140 F in less than 10 minutes and reaches 180 F in 15 to 20 minutes. Does this pose a threat of corrosion for the boiler from flue gas condensation?