York DF078 Series User's, Maintenance And Service Information Manual

Contents

035-19047-002-A-11032 Unitary Products GroupSAFETY INFORMATIONFOR YOUR SAFETY• Make sure that the furnace area is clear and free ofcombustible materials, gasoline and other flamma-ble vapors and liquids.• Be sure the furnace is clear and free of insulatingmaterial. Examine the furnace area after installa-tion of the furnace or the installation of additionalinsulation. Some types of insulation are combusti-ble.• For proper operation of this furnace, air for com-bustion and ventilation is required. Make sure thatthese openings are not obstructed.• For lighting or shutting down this furnace, refer tothe lighting instructions provided adjacent to theburners and also located in this manual.• A blocked vent roll-out switch is provided in theburner compartment. This switch is a manual reset.If the furnace fails to operate, contact a qualifiedservice technician.• Should the gas supply fail to shut off or if overheat-ing occurs, shut off the gas valve to the furnacebefore shutting off the electrical supply. Then call aqualified service technician.• Do not use this furnace if any part has been underwater. A flood-damaged furnace is extremely dan-gerous. Attempts to use the furnace can result infire or explosion. A qualified service technicianshould be contacted to inspect the furnace and toreplace all gas controls, control system parts, elec-trical parts that have been wet or the furnace ifdeemed necessary.• Determine the integrity of the installation regardingthe flue gas vent, the return and supply air duct.Confirm the equipment is well supported and thereare no signs of deterioration. The manufacturerrecommends that main burner, ignition device andcontrols are inspected by a qualified service techni-cian before each heating season.SYSTEM OPERATIONTHERMOSTATSSet your thermostat for either heating or cooling thenset it for the desired temperature. DO NOT ADJUSTTHE THERMOSTAT RAPIDLY ON AND OFF, ORBACK AND FORTH FROM HEAT TO COOL. THISCOULD DAMAGE YOUR EQUIPMENT.Always allow at least 5 minutes between changes. Findthe temperature that is most comfortable to you andthen LEAVE YOUR THERMOSTAT ALONE. (Excep-tion is for night or vacation “set back” to conserveenergy).Manually moving the thermostat up or down will notspeed up temperature changes in your rooms. Thisonly causes the thermostat switch to function at yourcommand rather than responding to room temperature.Heat generated by devices other than the furnace mayinterfere with thermostat performance. Therefore,lamps, radios, television sets, etc. should not be placednear the thermostat.INTERMITTENT IGNITION DEVICEWhen the thermostat calls for heat, gas is supplied andat the same time, sparking occurs to light the burner.With the burner lit, the flame sensor rod closes a circuitto the ignitor control which allows the burner to con-tinue to fire.When the room thermostat is satisfied, the electricalcircuit to the gas valve is opened, closing main burnergas. If the burner should fail to light, contact your heat-ing contractor or gas utility for service to insure thatproper operating conditions are restored.FIGURE 1- TYPICAL THERMOSTATThis furnace is equipped with an intermittent auto-matic ignition system. Do Not attempt to manuallyrelight the burners. Personal injury could result.