Furnace Operation ................................................................................................................................................ 26
Measure Gas Supply Pressure ............................................................................................................................ 27
Measure Natural Gas Input Rate .......................................................................................................................... 28
Operational Checks ...................................................................................................................... 29
Burner Flame ......................................................................................................................................................... 29
Auxiliary Limit ....................................................................................................................................................... 29
High or Primary Limit ........................................................................................................................................... 30
Safety Circuit Description ........................................................................................................... 31
Integrated Ignition Control ................................................................................................................................... 31
Primary Limit ......................................................................................................................................................... 31
Auxiliary Limit ....................................................................................................................................................... 31
Rollout Limit .......................................................................................................................................................... 31
Pressure Switches ................................................................................................................................................ 31
Flame Sensor ........................................................................................................................................................ 31
Burner Box ............................................................................................................................................................ 31
Troubleshooting ........................................................................................................................... 32
Furnace Lockout ................................................................................................................................................... 32
Diagnostic Chart ................................................................................................................................................... 32
Maintenance.................................................................................................................................. 35
Filters ..................................................................................................................................................................... 35
Burners .................................................................................................................................................................. 37
Qualified Servicer Only ........................................................................................................................................ 37
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