Goodman GSM80704BN HVAC Furnace Manual

The Goodman GSM80704BN is a high-efficiency gas furnace with 80,000 BTU input capacity, 80% AFUE rating, single-stage operation, multi-speed blower motor, electronic ignition system, aluminized steel heat exchanger, pressure switch safety controls, and compatibility with standard thermostat systems. Designed for residential forced-air heating applications with natural gas or propane capability. Below are key sections for safety, features, installation, setup, operation, and troubleshooting.

Features at a Glance

Key components: Aluminized steel tubular heat exchanger, induced draft combustion system, hot surface ignitor, multi-speed direct drive blower, pressure switches, flame sensor, gas valve, and control board.

Installation

Unpack and inspect contents. Position furnace in approved location.

1. Gas connection: Use black iron pipe with proper thread sealant; install sediment trap.
2. Vent system: Install PVC vent pipes per local codes; maintain proper slope.
3. Electrical: Connect 120VAC power supply; install proper disconnect switch.
4. Ductwork: Connect supply and return ducts; ensure proper sealing.
5. Thermostat: Connect 24VAC thermostat wires to control board.

WARNING! Gas furnaces produce carbon monoxide; proper venting is critical. Installation must comply with local codes and be performed by qualified technician.

First-Time Setup

Complete installation checks before initial startup.

1. Gas pressure check: Verify incoming and manifold pressures per specifications.
2. Vent verification: Confirm proper draft and vent pipe installation.
3. Electrical checks: Verify proper voltage and grounding.
4. Blower speed: Set appropriate CFM for heating application.
5. Combustion analysis: Verify proper combustion parameters.

CAUTION! Never operate furnace without proper venting. Ensure gas connections are leak-free before startup.

Specifications

• Input Capacity: 80,000 BTU/H
• AFUE Rating: 80%
• Gas Type: Natural gas or propane (with conversion kit)
• Electrical: 120VAC, 60Hz, 6.5 amps
• Blower Motor: Multi-speed direct drive
• Heat Exchanger: Aluminized steel tubular
• Vent Size: 2-inch or 3-inch PVC
• Gas Connection: 1/2-inch NPT
• Dimensions: Standard upflow configuration
• Warranty: Limited lifetime heat exchanger, 10-year parts

Controls and Settings

Integrated control board with diagnostic LED indicators. Gas valve with manual shutoff. Blower speed taps for airflow adjustment.

Control Board: LED status lights for normal operation and error codes. Automatic reset after lockout. 3-minute blower-off delay.

Blower Speeds: Multiple speed taps for heating operation. Adjustable for proper airflow. Gas Pressure: Factory set for natural gas; adjustable for propane conversion. Limit Controls: Automatic high-limit protection. Pressure Switches: Prove proper vent operation.

Connecting Components

Gas supply: Black iron pipe with sediment trap. Electrical: 120VAC power and thermostat connections. Vent: PVC pipe system. Ductwork: Supply and return air connections.

1. Turn off gas and electrical power before making connections.
2. Use proper pipe thread sealant rated for gas service.
3. Maintain proper vent pipe slope (1/4" per foot minimum).
4. Ensure all electrical connections are tight and properly grounded.

Tip: Always pressure test gas connections before energizing system.

Operating Procedures

Normal heating cycle operation sequence.

1. Thermostat calls for heat: Sends 24V signal to control board.
2. Inducer motor starts: Creates combustion air flow.
3. Pressure switch proves: Confirms proper draft establishment.
4. Hot surface ignitor heats: Glows for 17-30 seconds.
5. Gas valve opens: Fuel flows to burners.
6. Flame sensor proves: Confirms ignition success.
7. Blower motor starts: Circulates heated air after heat exchanger warms.
8. Cycle completion: Thermostat satisfied, gas valve closes, blower continues cool-down.

WARNING! Never attempt to manually override safety controls. If furnace fails to operate, contact qualified service technician.

Safety Features

Multiple safety systems: Flame rollout switches, high limit switches, pressure switches, flame sensor, ignitor control, and blower door safety switch. All systems must be functional for furnace operation.

Maintenance & Cleaning

Annual professional maintenance recommended. Monthly filter changes during heating season. Keep area around furnace clean and unobstructed.

CAUTION! Turn off gas and electrical power before performing any maintenance. Only qualified technicians should service gas and electrical components.

Regulatory Information

ANSI Z21.47/CSA 2.3: Certified for natural gas and propane operation. UL listed. Must be installed in accordance with National Fuel Gas Code (NFPA 54) and local codes. For technical support, contact Goodman Manufacturing at 1-877-466-8626 or visit www.goodmanmfg.com.

Troubleshooting

Reset: Power cycle furnace to clear temporary lockouts.

Service: 1-877-466-8626; www.goodmanmfg.com