From inside (document excerpt):
58DFA, 58GFA Induced-Combustion Furnaces Service and Maintenance Instructions For Sizes 065-150 Series 120 NOTE: Read the entire instruction manual before starting the installation. Index Page SAFETY CONSIDERATIONS .1 CARE AND MAINTENANCE 1-8 Air Filter Arrangement 2-3 Blower Motor and Wheel 3-4 Cleaning Heat Exchanger 4-5 Electrical Controls and Wiring .5-6 Pilot .6 Troubleshooting 6 Unit Wiring Diagram 7 Troubleshooting Chart 8 SAFETY CONSIDERATIONS Installing and servicing heating equipment can be hazardous due to gas and electrical components.
Only trained and qualified personnel should install, repair, or service heating equipment. Untrained personnel can perform basic maintenance functions such as cleaning and replacing air filters. All other operations must be performed by trained service personnel. When working on heating equipment, observe precautions in the literature, on tags, and on labels attached to or shipped with the unit and other safety precautions that may apply. Follow all safety codes. In the United States, follow all safety codes including the National Fuel Gas Code NFPA No. 541992/ANSI Z223.1-1992 (NFGC). In Canada, refer to the current edition of the National Standard of Canada CAN/CGA-B149.1and .2-M91 Natural Gas and Propane Gas Installation Codes (NSCNGPIC). Wear safety glasses and work gloves. Have fire extinguisher available during start-up and adjustment procedures and service calls. Recognize safety information. This is the safety-alert symbol. When you see this symbol on the furnace and in instructions or manuals, be alert to the potential for personal injury. Understand the signal word DANGER, WARNING, or CAUTION. These words are used with the safety-alert symbol. DANGER identifies the most serious hazards which will result in severe personal injury or death. WARNING signifies a hazard that could result in personal injury or death. CAUTION is used to identify unsafe practices which would result in minor personal injury or product and property damage. NOTE is used to highlight suggestions that will result in enhanced installation, reliability, or operation. ® ama CANADIAN GAS ASSOCIATION A PP R O VED R Fig. 1–Model 58DFADownflow A92058 Fig. 2–Model 58GFA Upflow A92057 Manufacturer reserves the right to discontinue, or change at any time, specifications or designs without notice and without incurring obligations. Book 1 4 PC 101 Catalog No. 565-801 Printed in U.S.A. Form 58D,G-3SM Pg 1 11-93 Replaces: 58D,G-2SM Tab 6a 8a The ability to properly perform maintenance on this equipment requires certain expertise, mechanical skills, tools, and equipment. If you do not possess these, do not attempt to perform any maintenance on this equipment other than those procedures recommended in the User’s Manual. FAILURE TO FOLLOW THIS WARNING COULD RESULT IN POSSIBLE DAMAGE TO THIS EQUIPMENT, SERIOUS PERSONAL INJURY, OR DEATH. CARE AND MAINTENANCE For continuing high performance and to minimize possible equipment failure, it is essential that periodic maintenance be performed on this equipment. Consult your local dealer as to the proper frequency of maintenance and the availability of a maintenance contract. Table 1–Filter Size Information for Downflow Furnace (In.)