Rule of thumbs

j a_2

I am not a huge fan of rules of thumb to finalize a question...However just to confirm my understanding, can it be said in ONE pipe steam, counter or parell flow, if you have an existing 2 inch main then your replacement boiler should not be bigger than 387 sq. ft. of steam...Does that make sense?  thanks  J A

DanHolohan

Well,

that would be the normal limit for a 2" main. in that system. 

Charlie from wmass

And as Dan will agree I am sure

Just because that is the limit on the size it does not mean that the system is that size. I have seem systems put in by dead men that the main was undersized from day one. Low bidders got jobs back in the day too.