An electric furnace uses resistance calrods to create heat directly 
            in the air stream.  Inside the jacket or cabinet will be controls, a 
            blower, and the circuit breakers for the heating elements. Some 
            furnaces have the breakers accessible from the outside of the 
            cabinet.
MRW Mechanical Information Center
HEAT LOSS
            It’s basic components are; the cabinet or jacket, a blower, heating 
            elements, and controls.
            Accessories can include: an air filter, electronic air cleaner, or 
            high performance media filter; humidifier, or air conditioning 
            evaporator coil. A system with central air might have a condensate 
            pump to remove the water generated in the dehumidifying process of 
            the air conditioning.
            A zone control panel and motor actuated dampers will be attached to 
            the furnace or ductwork if the system is zoned.
            Routine maintenance includes monthly replacing the air filter or 
            washing the electronic air cleaner grids during constant use, and 
            cleaning the humidifier. Humidifiers can be of the steam generating 
            type, which will be line voltage powered, and should be shut off 
            before servicing. Deadly high voltage conditions exist inside the 
            cabinet; leave control servicing to a qualified technician.
            Basic troubleshooting:
              The thermostat must be set higher than the actual room 
              temperature. If the thermostat is programmable, be certain it has 
              fresh batteries. 
              If there is central air, or the system is zoned, make sure the 
              selector switch is on heat. 
              If you are familiar with the fuse or circuit breaker panel, check 
              for blown fuses or tripped breakers. Correct the problem once. If 
              it repeats, call a serviceman. 
              Do not attempt to service the controls inside the cabinet. Deadly 
              high voltage conditions exist.