I'm taking it that you bought the place with new unit already installed-find out what size unit could be the unit is too small.Or thermostat needs replaced-hang a thermometer on closes vent to unit and see what it reads to get idea.Insulation in attic should be at least 4 inches think
You have to start with insulation as most of your heat is going out the ceilingYou probably have a heat pump and that would explain the air not being hotFor more info about how the system works, check out the heat pump page at my sourceAlso, closing the vents is not going to help.
Sounds like the size (BTU) of the furnace is insufficient for the structure and level of insulationRemember, it wasn't all that long ago that virtually no one had insulationThe heater can keep up if it is properly sized(Of course it is wasting energy - but right now the issue is warmth.) 30 F is not that cold for the heater to struggleI have an old 500 sq-ft stand alone office building with no insulation (built in 1917)The oil burner is 50,000 BTU and has no trouble keeping it any temperature I set(Yes - no insulation more moneyAm insulating next month actually.) Grandmothers 1890 vintage home, 1200 sq-ft, no insulation is comfortably heated with a 90,000 BTU oil burner.
Here you go; 1 cup confectioners' sugar 3 3/4 cups white sugar 1 1/2 cups light corn syrup 1 cup water 2 teaspoons cinnamon oil 1 teaspoon red food coloring Roll the edges of two 16 inch square pieces of heavy duty aluminum foilSprinkle the foil very generously with confectioners' sugarIn a large heavy saucepan, combine the white sugar, corn syrup, and waterHeat over medium-high heat, stirring constantly until sugar dissolvesStop stirring, and boil until a candy thermometer reads 300 to 310 degrees F (149 to 154 degrees C)Remove from heatStir in the cinnamon oil and food coloringPour onto the prepared foil, and allow to cool and hardenCrack into pieces, and store in an airtight containerServes 48-
You found your problem.in the attic.all your heat is going out the roof and the house doesn't have a chance to heat.
