What information do I need to know to get the correct size boiler to replace my oil fired boiler. I should be able to get enough information from my existing boiler to determine the requirements for purchasing a replacement gas boiler.
BTUs of old boiler would be a good start. Also, the guys you'll buy your new gas boiler from will have oodles of info. Mind you, Ebay might be cheaper so you'd end up going back to one of your "pay" sites.