An oil fired warm air furnace uses no.2 fuel oil burned in a sealed chamber to heat an exchanger. Then with the help of a blower or fan, forces air across the exchanger, into ductwork to warm the structure.
It’s basic components are: the burner, heat exchanger, fire box, blower, and cabinet, sometimes known as the jacket. Accessories that can be installed inside or outside of the unit include: a fan center(usually a low voltage relay that can turn the blower on independent of the heat cycle), an air filter, electronic air cleaner, or high performance media filter, humidifier, and air conditioning evaporator coil . With central air, sometimes a condensate pump will be used to remove the water discharged in the dehumidification action of the air conditioning.
A zone control panel and motor actuated dampers will be present on the furnace or ductwork if the system is zoned. Routine maintenance includes; monthly filter replacement or washing the electronic air cleaner grids when in constant use, cleaning the humidifier if so equipped, and an annual tune up of the burner.
An oil burner tune up includes a nozzle and filter replacement, heat exchanger and smoke pipe cleaning, and a fuel to air mixture adjustment. Since the mixture adjustment requires the use of special instruments to meet federal standards, it is best left to a professional to obtain peak efficiency.
Basic Troubleshooting: First check that the thermostat is set higher than the actual room temperature. If you have a programmable thermostat, check that it has fresh batteries. If equipped with central air, or the system is zoned, make certain the selector switch is on heat. Check that the emergency switch (usually a red switch plate at the top of the cellar stairs or on the side of the furnace) is on. If you are familiar with the fuse or circuit breaker panel, see if the fuse is burned or the breaker is tripped. Correct the problem once; if the fuse blows or breaker trips again, call a serviceman.
If you can access the burner, check the red button on the protecto relay. Older furnaces will have a stack limit switch mounted on the smoke pipe that connects the furnace to the chimney. Push the button one time only. Repeated attempts to fire the burner without ignition can create an explosive condition. If the burner fails to fire and continue running on its own, call for service.