Fred, thanks your fine advice and suggestions. Regarding your point #1) I have been told I can convert the existing radiators for the hot water system by removing the steam traps and adding vents. Contractors have explained this as a very simple process. However, the radiators are "old" and with the very hard H2O, who knows how corroded, same with the existing pipes (except for the new pipes installed at the cracked boiler). #2) I will definitely need some sort of water filtration/conditioning system installed if I stay with the steam system. #3) Curious as to why you decided to switch from furnace to hot water heat at the cost involved, how did you arrive at this decision. Can you supply any pros and cons comparing the 2 systems. #5) I currently have 3 bids, however, it is extremely difficult because, as you say, they all quote differently making it impossible to compare "apples to apples". I am comparing an apple, a pear and an orange?????? Finally, please explain what I should be looking for with "heat loss calculations". I know at least 1 contractor who supplied bid did this calculation, but did not share info with me other than suggestion to add attic insulation along with replacing the system (would only quote on replacing steam, would not quote on hot water system, stated it would not work). Thanks again for all your help on this.