I live just East of Des Moines. The living area of my current home is right around 3k sqft, and I'm building an addition that is more than doubling the size of my current home, plus a large attached garage. I plan on stubbing radiant heat water lines into the garage, but don't plan on heating it initially in order to make sure the boiler can handle the load of the rest of the house. My house is a two level walkout ranch style built into the side of a hill, so in the back there is one level above grade and in the front there are two levels above grade. Baseboard heat in the lower level and radiant floor heating plus baseboard heat in the upper level. It's a brick home with R21 fiberglass insulated 5.5" external timber framed walls, quality windows, and R60 blown in cellulose insulation in the attic. I will run R30 fiberglass insulation in the garage ceiling, (due to living area above garage), and R21 fiberglass insulation in the wall that separates the garage from the mud room. So, it is and will be a pretty well insulated structure. The radiant floor heating system in the upper level covers a lot of square footage and is great at distributing the heat evenly. The baseboard heat in the lower level doesn't do as good a job as the radiant floor heat, but because it's 1/2 under grade, it's relatively pleasant on the lower level year round without running heat or AC.
I am currently running a Viessmann Vitodens 200 propane boiler that will remain hooked up and become strictly a backup system in emergencies. The Viessmann is super high efficiency and sized right for my current home, and yet my monthly budget billing for propane is still $200 per month, 12 months a year. That's ridiculousness in my opinion and doubling that to heat my home after the addition is completely outrageous. That's why I'm moving to an OWB and want to make sure I'm spending my money wisely and not inheriting a huge headache and buyers remorse with my purchase. I've got plenty of timber to cut and already have a couple years worth of dried hardwood stacked and ready to burn. I've wanted to get an OWB since we bought our place 4 years ago, but decided to wait to buy one big enough to heat everything after we had finished doing what we wanted to do with our home.
That's the long version of my situation. The short is that I will be heating a 6k+ sqft home, via radiant floor heating and baseboard systems, plus DHW. I really like the current NCB-325G model boiler and believe it would do a fine job heating my home without needing to feed it more than twice a day, (on average). The older NCB-325 model from pre 2009 is the unit that I am questioning specifically. It's only been used for two heating seasons, (2011-12 & 2012-13), and is priced under a new largest Ridgewood model. Is the older used NCB-325 model a good quality boiler that will heat my home and preform the way I want it to, or should I spend the extra money and get a new NCB-325G?
I've gone the route of buying, selling and replacing things in the past and I don't enjoy the additional hassle. I'd rather buy once, cry once if it means I'm making the right buy the first time. I've got my hands full with building my addition right now that I am looking forward to relaxing a bit after I'm done. If the boiler ends up being too small to do the job, my relaxation will be cut short.
Thanks again, BID