Service and Troubleshooting
80% Single Stage Gas Furnaces
GM9S80, AM9S80, GC9S80, AC9S80, VM9S80, VC9S80 & Accessories
Copyright © 2021 Goodman Manufacturing Company, L.P.
RS6621008
July 2021
TABLE OF CONTENTS
IMPORTANT INFORMATION ............................................ 2
PRODUCT IDENTIFICATION ........................................... 4
SYSTEM OPERATION ...................................................... 5
SCHEDULED MAINTENANCE ....................................... 25
SERVICING ..................................................................... 29
CHECKING VOLTAGE .............................................. 30
CHECKING WIRING .................................................. 30
CHECKING THERMOSTAT, WIRING ....................... 30
CHECKING TRANSFORMER AND CONTROL
CIRCUIT ...................................................................... 31
CHECKING AIR CIRCULATOR BLOWER MOTOR 31
CHECKING DUCT STATIC ........................................ 32
CHECKING TEMPERATURE RISE .......................... 32
CHECKING PRIMARY LIMIT CONTROL ................. 33
CHECKING AUXILIARY LIMIT CONTROL ............... 33
CHECKING FLAME ROLLOUT CONTROL ............. 34
INDUCED DRAFT BLOWER MOTOR ...................... 35
CHECKING GAS VALVE (REDUNDANT) ................ 35
CHECKING MAIN BURNERS ................................... 35
CHECKING ORIFICES .............................................. 35
CHECKING GAS PRESSURE .................................. 36
CHECKING HOT SURFACE IGNITER ..................... 38
CHECKING FOR FLASHBACK ................................. 38
CHECKING PRESSURE SWITCH............................ 38
HIGH ALTITUDE APPLICATION ............................... 39
CHECKING FOR DELAYED IGNITION .................... 39
CHECKING INTEGRATED IGNITION CONTROL
BOARDS ..................................................................... 40
CHECKING FLAME SENSOR ................................... 40
AIRFLOW TABLES ........................................................ 42
1 STAGE STATUS CODES ........................................... 50
1 STAGE TROUBLESHOOTING CODES.................... 52
WIRING DIAGRAMS ....................................................... 54
Pride and workmanship go into every product to provide
our customers with quality products. It is possible, however,
that during its lifetime a product may require service.
Products should be serviced only by a qualified service
technician who is familiar with the safety procedures
required in the repair and who is equipped with the proper
tools, parts, testing instruments and the appropriate service
manual.
REVIEW ALL SERVICE INFORMATION IN THE
APPROPRIATE SERVICE MANUAL BEFORE
BEGINNING REPAIRS.
Only personnel that have been trained to install, adjust,
service or repair(hereinafter, “service”) the equipment
specified in this manual should service the equipment. The
manufacturer will not be responsible for any injury or
property damage arising from improper service or service
procedures. If you service this unit, you assume responsi
-
bility for any injury or property damage which may re
-
sult. In addition, in jurisdictions that require one or more
licenses to service the equipment specified in this manual,
only licensed personnel should service the equipment.
Improper installation, adjustment, servicing or repair of
the equipment specified in this manual, or attempting to
install, adjust, service or repair the equipment specified in
this manual without proper training may result in product
damage, property damage, personal injury or death.
WARNING
