I live in NH and have a 2300 square foot colonial that's currently being heated via oil boiler with forced hot water baseboard elements. I've been looking into the Harman pellet boilers to tie into the existing distribution system. The idea is to keep the oil boiler in place in case we ever sell the house but not use it once the pellet boiler is installed. I have heard some say that the Hydroflex60 can properly and efficiently heat a house my size or larger. I wanted to get some opinions on the matter from those of you that might have experience with this unit. I'd like to offer a little more info. The house was built in 1999. it's your typical cookie cutter contractor grade colonial that you see everywhere in New England. this winter I noticed the origianal factory weatherstripping on the windows was not doing it's job so I replaced it with some new stuff from Lowes. We have been keeping the thermostat at 64 when using oil to conserve money but I'd like to run it around 67-68 with the pellet boiler for a little extra comfort. Also I have an outdoor temperature reset unit hooked up to the oil boiler. Do they make these units to go with the pellet boilers to increase efficieny? I hope that the hydroflex60 will get the job done and that I won't have to spend the extra money for the pb105. Any advice/info would be greatly appreciated. Thanks guys.