I’m looking into the heat master g100 boiler and have a few questions for you experts out there! House is 1800 sq ft 2 story, built in 1983,(900 sq ft per floor) moderately insulated, new windows. I have a propane air forced unit that does the main floor, and a separate system for the 2nd floor which is a heat pump with electric back up heat. 2nd floor never had heat/air when we bought the house, just installed it upstairs 2 yrs ago. Now, would I run the pex pipe up the back of the house like my line set is for the upstairs unit? Insulated of course! But I will also be building a 1200 sq ft garage right next to the house that I wouldn’t mind running heat into either. Would I be asking too much from the 100 series to do this? Would be 3000 sq ft total and would like to heat water along with it. I live in southwest Ohio. Thank you for any info I receive.