I'm just south of you in Connecticut and my home is heated by a steam system as well. Steam is a very unique heat delivery system so you need to calculate your home's BTU needs differently than a hot water or hot air system. Like Mike above mentioned, you should calculate your home's radiation needs. Essentially that means you determine the size of all your radiators in your home and count them. To this figure you will add a "pick-up factor" to account for the radiation requirments of the steam delivery pipes in your home. Don't be intimidated, it's not as difficult as it may appear. The radiator figures are dependent on their size in terms of width, height, length and number of columns. The calculations for the radiators have actually already been done and in a specific book, of which I can assist you with.
One of the best resources for learning about steam is a book by Dan Holohan called "The Lost Art of Steam Heating". I can't say enough good about the book. Steam heating profesionals are few and far between. The book will really help you with any of your steam heating questions and problems.
Don't be tempted to guess your btu requirements by looking at your current oil fired boilers btu output. You'd be much better served by calculating your radiation needs.
Is your home a 'one pipe' or 'two pipe' system? How many radiators do you have in your entire house? Do you have any banging sounds or hissing sounds? Can you post pics of your boiler and the steam pipes near it?
Ray, steam, when done correctly, is one of the best heating methods. The 'Deadmen' knew what they were doing. Coal is what initially fired these steam systems. Go back to it and you'll be amazed at the efficiency and warmth.
Last edited by Townsend
on Thu Nov 15, 2012 11:35 am, edited 2 times in total.