INSTALLATION MANUAL

167187-UIM-B-0306GASPIPEMANUALSHUT-OFFVALVEGASPIPEDRIPLEGGAS BURNERSGAS VALVEGas piping may be connected from either side of the furnace using anyof the gas pipe entry knockouts on both sides of the furnace. Refer toFigure 1 dimensions.GAS ORIFICE CONVERSION FOR PROPANE (LP)This furnace is constructed at the factory for natural gas-fired operation,but may be converted to operate on propane (LP) gas by using a factory-suppliedLP conversion kit. Follow the instructions supplied withthe LP kit. Refer to Table 6 or the instructions in the propane (LP) conversionkit for the proper gas orifice size.DRIPLEGFIGURE 8: Horizontal Gas PipingMANUALSHUT-OFF VALVEIMPORTANT: An accessible manual shutoff valve must be installedupstream of the furnace gas controls and within 6 feet (1.8 m) of the furnace.The furnace must be isolated from the gas supply piping system byclosing its individual external manual shutoff valve during any pressuretesting of the gas supply piping system at pressures equal to or lessthan 1/2 psig (3.5 kPa).The gas valve body is a very thin casting that cannot take anyexternal pressure. Never apply a pipe wrench to the body of the gasvalve when installing piping. A wrench must be placed on the octagonalhub located on the gas inlet side of the valve. Placing a wrenchto the body of the gas valve will damage the valve causing improperoperation and/or the valve to leak.LoNOx furnaces requiring propane (LP) gas must have the LoNOxscreens removed prior to installation and operation. See theinstructions supplied with the propane conversion kit or the start upprocedure at the back of these instructions on proper removal of theNOx screens.HIGH ALTITUDE GAS ORIFICE CONVERSIONThis furnace is constructed at the factory for natural gas-fired operationat 0 – 8,000 feet (0-m – 2,438 m) above sea level.The manifold pressure must be changed in order to manitain properand safe operation when the furnace is installed in a location where thealtitude is greater than 8,000 feet (2,438 m) above sea level. Refer to toTables 6 & 7 for proper manifold pressure settings.HIGH ALTITUDE PRESSURE SWITCH CONVERSIONFor installation where the altitude is less than 8,000 feet (2,438 m), it isnot required that the pressure switch be changed. For altitudes above8,000 feet (2,438 m), see Table 17 Field Installed Accessories - HighAltitude Pressure SwitchTABLE 6: Nominal Manifold Pressure - High FireGas Heating Value(BTU/cu ft.)Single/Second Stage Manifold Pressures (in wc)Single/Second Stage Manifold Pressures (kpa)Altitude (feet)Altitude (m)0-7999 8000-8999 9000-9999 0-2437 2438-2742 2743-3048800 3.5 3.5 3.529.8 0.87 0.87 0.87850 3.5 3.5 3.5 31.7 0.87 0.87 0.87900 3.5 3.5 3.5 33.5 0.87 0.87 0.87950 3.5 3.5 3.3 35.4 0.87 0.87 0.811000 3.5 3.2 2.9 37.3 0.87 0.80 0.731050 3.5 2.9 2.7 39.1 0.87 0.73 0.671100 3.2 2.7 2.4 41.0 0.80 0.66 0.612500 (LP) 9.8 8.2 7.5 93.2 (LP) 2.44 2.03 1.86Gas Heating Value(MJ/cu m)TABLE 7: Nominal Manifold Pressure - Low FireGas Heating Value(BTU/cu ft.)First Stage Manifold Pressures (in wc)First Stage Manifold Pressures (kpa)Altitude (feet)Altitude (m)0-7999 8000-8999 9000-9999 0-2437 2438-2742 2743-3048800 1.7 1.7 1.729.8 0.42 0.42 0.42850 1.7 1.7 1.7 31.7 0.42 0.42 0.42900 1.7 1.7 1.7 33.5 0.42 0.42 0.42950 1.7 1.7 1.5 35.4 0.42 0.42 0.381000 1.6 1.5 1.4 37.3 0.41 0.37 0.341050 1.5 1.4 1.3 39.1 0.37 0.34 0.311100 1.3 1.2 1.1 41.0 0.34 0.31 0.282500 (LP) 4.1 3.8 3.5 93.2 (LP) 1.03 0.95 0.87Gas Heating Value(MJ/cu m)8 Unitary Products Group