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Gregory HoffmanSep 12, 2025
What to do if my Goodman GC9S80 Furnace twinning feature is not working?
- JJason BellSep 12, 2025
If the twinning feature is not working on your Goodman Furnace due to a TWIN Error, check for wiring connections.
To Next PageTo Next PageWhat to do if my Goodman GC9S80 Furnace twinning feature is not working?
If the twinning feature is not working on your Goodman Furnace due to a TWIN Error, check for wiring connections.
What to do if my Goodman GC9S80 fails to operate due to Internal Faults?
If your Goodman Furnace fails to operate due to Internal Faults or IRQ Loss in the Control Board, replace the integrated control board.
General| Model | GC9S80 |
|---|---|
| AFUE Rating | 80% |
| Heat Exchanger Material | Aluminized Steel |
| Fuel Type | Natural Gas |
| Stages | Single Stage |
| Cabinet | Heavy Gauge Steel |
| Vent Size | 4 inches |
Contains critical warnings regarding electrical shock, flammable materials, and high voltage hazards.
Details startup, heating, cooling, and fan-only sequences, including delays.
Step-by-step guide for safely starting up the furnace for the first time.
Describes the operational sequence when the furnace calls for heat.
Details the operational sequence for low stage and second stage cooling.
Step-by-step guide for safely shutting down the furnace.
General warnings and cautions for installation, adjustment, and operation.
Guidance on selecting an appropriate and safe location for furnace installation.
Details requirements for providing adequate air for combustion and ventilation.
Covers methods for calculating and providing combustion air requirements.
Methods for determining and providing indoor air for combustion.
Methods for calculating and providing outdoor air for combustion.
Guidance on using a mix of indoor and outdoor air for combustion.
Details requirements for Category I venting for 80% furnaces.
Warnings and considerations for venting through masonry chimneys.
Annual service checks for furnace components to ensure proper working order and function.
Procedure for checking the gas valve's manual and automatic control functions.
Measuring and adjusting inlet and manifold gas pressures for proper furnace operation.
Troubleshooting the integrated ignition control for flame sensing and lockout issues.
Procedure to check flame sensor signal, continuity, and cleaning.
Lists symptoms, LED status, fault descriptions, and corrective actions for furnace operation.
Additional fault descriptions and corrective actions for furnace operation.
