From inside (document excerpt):
58STA/STX 4-Way Multipoise Induced-Combustion Gas Furnace Input Capacities: 45,000 thru 155,000 Btuh Product Data THE CARRIER 58STA/STX GAS FURNACE The 58STA/STX 4-way Multipoise Gas Furnaces feature Carrier’s QuieTechTM noise reduction system for incredibly quiet induced draft operation. Applications are easy with 4-way multipoise design, throughthe-furnace downflow venting, 13 different venting options, and a door designed for easy service access.
An inner blower door is provided for tighter sealing in sensitive applications. The 58STA/STX furnaces are approved for use with natural or propane gas, and the 58STX is approved for use in Low NOx Air Management Districts. STANDARD FEATURES QuieTechTM system noise reduction system Microprocessor based control center LED diagnostics and self test feature Adjustable heating air temperature rise Adjustable cooling airflow 4-way Multipoise furnace, 13 vent applications Compact design only 33-1/3 in. tall Power HeatTM Igniter Draft safeguard switch to ensure proper furnace venting Inner door for tighter sealing Hybrid HeatTM compatible All models are chimney friendly when used with accessory vent kit Twinning in Upflow, Downflow and Horizontal Residential installations eligible for consumer financing through the Retail Credit Program A04039 LIMITED WARRANTY 20-year warranty on “Super STM ” heat exchanger 5-year parts warranty on all other components J2 90 120 150 180 1 2 3 4 5 J1 G Com W Y 24V R TEST/TWIN HUM 3-AMP FUSE SEC-1 EAC-2 58STA/STX PRI A02169 A02015 A02170 HEAT EXCHANGER CONTROL BOARD I NDUCER BL OWER Model number nomenclature 58STA 045 100 58STA 4-Way Multipoise 58STX Low NOx version 08 Nominal Cooling Size (Airflow at .5 ESP) (400 CFM per 12,000 Btuh) 08 — 800 CFM 12 — 1200 CFM 14 — 1400 CFM 16 — 1600 CFM 20 — 2000 CFM 22 — 2200 CFM Input Capacity 045 — 44,000 Btuh 070 — 66,000 Btuh 090 — 88,000 Btuh 110 — 110,000 Btuh 135 — 132,000 Btuh 155 — 154,000 Btuh Series Number 2 Furnace components INDUCER MOTOR ASSEMBLY VENT BELOW MAIN LIMIT SWITCH (BEHIND GAS VALVE) PRESSURE SWITCH DRAFT SAFEGUARD SWITCH GAS VALVE GAS MANIFOLD MANUAL RESET LIMIT SWITCHES GAS BURNER FLAME SENSOR HOT SURFACE IGNITE R BLOWER DOOR SAFETY SWITCH BLOWER AND MOTOR RATING PLATE NOT SHOWN (LOCATED ON BLOWER DOOR) *Elbow may be turned to a different position, depending on type of installation NOTE: The 58STA/STX Furnaces are factory shipped for use with natural gas. These furnaces can be field-converted for propane gas with a factory-authorized and listed accessory conversion kit. CONTROL 3 58STA/STX FLUE COLLECTOR BOX Carrier accessories ON Electronic High Efficiency Air Filtration System OFF Cell Energized Input Power JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC A97432 A02121 CONTROLS: THERMOSTATS AND ZONING Available in programmable and non-programmable models, Carrier thermostats maintain a constant, comfortable temperature level in the home. For the ultimate in home comfort, Carrier’s 2, 4, and 8-zone systems allow temperature control of individual “zones ” of the home.