From inside (document excerpt):
58CTA/58CTX 2 Stage Deluxe Induced-Combustion 4-Way Multipoise Furnace Installation, Start-up, Operating, and Service and Maintenance Instructions -Series 110 THE PERFORMANCE 80 GAS FURNACE The 58CTA/CTX Two-Stage, 4-way Multipoise Gas Furnaces offer unmatched comfort in their class with ComfortHeatTM Technology in an 80% AFUE gas furnace. You get the benefits of a ComfortHeatTM Technology furnace: reduced drafts, reduced sound levels, longer cycles, less temperature swings between cycles, and less temperature differences between rooms.
Its exclusive, intelligent microprocessor control adapts to the heating needs of the home by automatically adjusting high and low heat times to maximize comfort. The 58CTA/CTX furnaces are approved for use with natural or propane gas, and the 58CTX is also approved for use in Low NOx Air Quality Management Districts. CERTIFIED ® STANDARD FEATURES – ComfortHeatTM Technology Two-stage heating with single-stage thermostat Very low operating sound through low-stage operation and QuieTechTM system – Media Filter Cabinet Available – Microprocessor based “smart ” control center Adapts heating stages to meet demand Dehumidification selection for summer-time cooling Adjustable heating air temperature rise Adjustable cooling airflow ComfortFanTM–Constant fan speed selectable from thermostat LED diagnostics and self test feature Stores fault codes during power outages – 4-way Multipoise furnace, 13 vent applications – Hot surface ignition (HSI) – Draft safeguard switch to ensure proper furnace venting – All Models Chimney-Friendly when used with the accessory vent kit. – Insulated blower compartment – Heat pump compatible – Residential installations eligible for consumer financing through the Retail Credit Program – Twinning in Upflow, Downflow and Horizontal LIMITED WARRANTY – 20-year warranty on “Super STM ” heat exchanger – 5-year parts warranty on all other components Catalog No: 535-80124 Form No. 58CT-5SI 1-05 Important Information Addendum to the Installation, Start-up, and Operating and Maintenance Instructions Series 110 or Series B 33 1/3 ” Mid-Efficiency Furnaces This furnace is equipped with the White-Rodgers Series G valve. This instruction sheet is to familiarize you with Series G gas valve and to be used to check and adjust gas pressure for proper installation and start-up. This sheet will be used to complete the “Adjustments ” section of the “Start-up Procedures ” section of the Installation, Start-up, Operating and Maintenance Instructions. See Fig. 1 for two-stage gas valve. This version of the G valve has standard 1/8 ” NPT inlet and outlet pressure taps that are removed with a 3/16 ” hex head wrench for connection to a manometers and Low Gas Pressure Switch (when used). For conversions to propane gas, refer to the instructions in the Natural to Propane Conversion Kit, KGANP3001ALL. Fig. 1-Two-Stage Gas Valve The major difference in the two-stage G valve, besides the compact design, is the location of the Low and High stage regulators. Both regulators are located on top of the valve and are marked “Lo ” and “Hi ” next to the regulator seal caps. Both regulator springs are adjusted with a standard 3/16 ” or smaller flat-tipped screwdriver. The other difference is the G series valve IS NOT a dual-fuel gas valve.