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INSTALLATION
INSTRUCTIONS
CAUTION: READ ALL SAFETY GUIDES
BEFORE YOU START TO INSTALL
YOUR FURNACE.
SAVE THIS MANUAL
ALL POSITION
AUTOMATIC IGNITION FURNACES
G8C / FG8 SERIES MODELS
50 - 125 MBH INPUT
UPFLOW / HORIZONTAL
AUTOMATIC IGNITION FURNACES
G8C / FG8 SERIES MODELS
150 MBH INPUT
035-15241-003 Rev. A (201)
TABLE OF CONTENTS
GENERAL INFORMATION . . . . . . . . . . . . . . . . . . . . . . . 2
FURNACE SPECIFICATIONS . . . . . . . . . . . . . . . . . . . . 3
PRE-INSTALLATION INSPECTION . . . . . . . . . . . . . . . . 4
CODE COMPLIANCE . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
INSTALLATION POSITION
(50-125 MBH Models) . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
INSTALLATION POSITION
(150 MBH Models) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
CONVERSION INFORMATION
(50-125 MBH Models) . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
TO CONVERT FROM DOWNFLOW TO UPFLOW
CONFIGURATION (50-125 MBH Models) . . . . . . . . . . . 4
TO CONVERT FROM UPFLOW TO DOWNFLOW
CONFIGURATION (50-125 MBH Models) . . . . . . . . . . . 5
FURNACE LOCATION . . . . . . . . . . . . . . . . . . . . . . . . . . 6
COMBUSTION AND VENTILATION AIR . . . . . . . . . . . . 7
FURNACE SIZING AND DUCT
SYSTEM DESIGN . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
RETURN AIR AND FILTERS . . . . . . . . . . . . . . . . . . . . . 9
GAS PIPING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
VENTING (CATEGORY I) . . . . . . . . . . . . . . . . . . . . . . . 13
SIDEWALL VENTING . . . . . . . . . . . . . . . . . . . . . . . . . . 15
ELECTRICAL WIRING . . . . . . . . . . . . . . . . . . . . . . . . . 15
WIRING DIAGRAM . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
PRE-OPERATIONAL CHECKS . . . . . . . . . . . . . . . . . . 19
SEQUENCE OF OPERATION . . . . . . . . . . . . . . . . . . . 19
FURNACE OPERATION . . . . . . . . . . . . . . . . . . . . . . . . 20
INSTALLATION CHECKS . . . . . . . . . . . . . . . . . . . . . . 21
SERVICE INSTRUCTIONS . . . . . . . . . . . . . . . . . . . . . . 22
REPLACEMENT PARTS . . . . . . . . . . . . . . . . . . . . . . . 22
EFFICIENCY
RATING
CERTIFIED