66399-YIM-C-040568 Unitary Products GroupOPERATING INSTRUCTIONSTO LIGHT PILOT AND MAIN BURNERS:1. Turn “off” electric power to unit.2. Turn room thermostat to lowest setting.3. Turn gas valve knob to “on” position.4. Turn “on” electric power to unit.5. Set room thermostat to desired temperature.(If thermostat “set” temperature is above room tem-perature, pilot burner ignition will occur and, afteran interval to prove pilot flame, main burners willignite).TO SHUT DOWN:1. Turn “off” electric power to unit.2. Depress knob of gas valve while turning to “off”position.POST-START CHECK LIST (GAS)After the entire control circuit has been energized andthe heating section is operating, make the followingchecks:1. Check for gas leaks in the unit piping as well as thesupply piping.2. Check for correct manifold gas pressures. See“Checking Gas Input” on page 69.3. Check the supply gas pressure. It must be withinthe limits shown on rating nameplate. Supplypressure should be checked with all gasappliances in the building at full fire. At no timeshould the standby gas line pressure exceed 13",nor the operating pressure drop below 5.0" fornatural gas units. If gas pressure is outside theselimits, contact the local gas utility for correctiveaction.This furnace is equipped with an intermittentpilot and automatic re-ignition system. DONOT attempt to manually light the pilot.FIRE OR EXPLOSION HAZARDFailure to follow the safety warning exactlycould result in serious injury, death or propertydamage.Never test for gas leaks with an open flame.use a commercially available soap solutionmade specifically for the detection of leaks tocheck all connections. A fire or explosion mayresult causing property damage, personalinjury or loss of life.FIGURE 19 - TYPICAL GAS VALVES
