Replacing a 25-year old Weil Mclain
We have a 25-year old Weil-Mclain boiler. It was the most efficient (93%) boiler we could find in 1986. It has been great: only replaced the electronic ignition in the first year and the circulator twice. It still works great but we have added 600 sq ft to our house and I am concerned that we will not have enough BTUs for the coldest days. We live in a fairly cold spot (around 8000 degree days) in the mtns of New Mexico. In the old days it was easy: go buy the best W-M, Burnham or Utica boiler you could afford and count on 30+ years out of them. My uncle used to own a fuel oil and furnace business and I helped him summers; so I know a fair amount about yesterday's technology. Today's technology frankly scares me: most units are sheet metal instead of cast iron. I hear one horror story after another about how the quest for 1--5% more efficiency leads to really serious problems. I also am loathe to give a plumber $8--10K to install a $1500 unit..
Does anyone have any advice on what direction to research?