Old furnace finally went out after almost 30 years last winter. Had a Crown oil boiler furnace as the replacement.I have baseboard heat. My homes heated living space is about 990 square feet,my ceilings are 8 feet high. No insulation in the walls(which is in the process of being taken care of)and the windows are single paned awning with another single pain insert on the inside of the home. The windows will get replaced in the spring with a much more energy efficiency. The attic is well insulated and the crawl space below the house,I'd say four feet from the ground is covered with a believe a 6 millimeter tarp and stones covering the whole living space of the home with fiberglass insulation under the flooring in the crawlspace. My boiler is a Crown,model (TWZ100bott1psu) The heating capacity is 120,000 BTU/HR and a Net Rating of 104,000 BTU/HR. I was in a jam as the old furnace went out during the coldest days of winter and could only get this one guy in on short notice to replace with this model. He told me the specs were fine for the size of my home. My question is, are they? Would have liked to have had a more efficient model put in, this boiler has an efficiency rating of 84.5%.Keep the heat on consistently at 68 degrees,no lower than 65 when not at home or I drop it at night before bed. Had an oil delivery approximately about one month ago to top it off and have just under 3/4 oil left in my 275 gallon tank,more towards 5/8 according to the reading.I live in North West New Jersey. Some very cold days so far the last couple of weeks. Is my model correct and do you think that that amount of oil burned in this period of time is ok? Thanks all for the info, Tom.