How It Works
An oil-fired furnace produces hot air to heat a home through
an air duct system. Oil-fired boilers - also called oil furnaces - produce hot
water or steam for a baseboard or radiator heating system, and for general hot
water use. Both systems burn oil from a tank that combusts through a burner
What Can Go Wrong?
A furnace has many components that can cause a failure, most
of which can be repaired by maintaining or by replacing individual pieces. Oil
sediment may clog filters and nozzles, causing the boiler to shut down or
combust poorly. The furnace blower motor can also be replaced if it fails. When
a combustion chamber fails in a hot air furnace or water leaks in a boiler
system, complete replacement is usually required.
Heating is the largest energy expense in most homes,
accounting for 35 to 50 percent of annual energy bills in colder parts of the
country. Oil furnaces range in size from 16 to 88 kilowatts (kW). The average
home using oil consumes 663 gallons per year for space heating, producing
approximately 14,800 pounds of carbon dioxide (CO2). Oil furnaces
and boilers are major energy consumers and sources of CO2.
Oil-fired furnaces are ranked according to their annual fuel
utilization efficiency (AFUE), which is a representation of the energy
efficiency of the furnace during the heating season. For oil-fired furnaces,
AFUE may be 60 percent for an old furnace and can range up to 92 percent for a
modern condensing furnace design. When replacing the furnace, it is important
to consider that the higher the AUFE, the lower the energy usage, energy cost
and CO2 footprint.