Goodman Forced Air Furnace Manual

The Goodman Forced Air Furnace is a high-efficiency heating system designed for residential use, featuring variable-speed blower motors, electronic ignition systems, multiple heat exchanger stages, and integrated safety controls. Below are key sections for safety, features, installation, setup, operation, maintenance, and troubleshooting.

1. Features at a Glance 2. Installation 3. First-Time Setup 4. Specifications 5. Controls and Settings 6. Connecting Thermostat 7. Operating Procedures 8. Maintenance Schedule 9. Care & Cleaning 10. Regulatory Information 11. Troubleshooting

Features at a Glance

Key components: Heat exchanger, blower assembly, gas valve, ignition system, pressure switches, limit switches, venting system.

Feature	Description
Heat exchanger	Stainless steel primary and secondary heat exchangers
Blower motor	Variable-speed ECM motor for efficient airflow
Gas valve	Electronic modulating gas valve for precise control
Ignition system	Hot surface ignition for reliable startup
Pressure switches	Safety switches to verify proper venting
Limit switches	High-temperature safety cutoffs
Control board	Microprocessor-based control system
Venting system	PVC vent pipes for sidewall or roof termination
Filter system	Standard 1-inch or 4-inch media filter compatibility
Diagnostic lights	LED status indicators for troubleshooting

Installation

Unpack and inspect all components. Ensure proper clearances and location requirements.

Position furnace: Place on level surface with proper clearances (typically 1" sides, 6" front, 24" top).
Connect gas line: Use black iron pipe with proper thread sealant; pressure test for leaks.
Install venting: Use approved PVC pipe with proper slope and termination clearances.
Electrical connections: Connect 120V power supply and thermostat wiring.
Ductwork: Connect supply and return ducts with proper sealing.

WARNING! Gas appliances require professional installation. Only qualified technicians should perform installation. Ensure proper combustion air and ventilation.

First-Time Setup

Complete installation verification and initial startup procedures.

Gas pressure check: Verify inlet and manifold pressures per specifications.
Venting verification: Confirm proper draft and vent pipe integrity.
Electrical checks: Verify proper voltage and thermostat connections.
Startup sequence: Turn on gas supply, power up furnace, set thermostat to heat mode.
Performance verification: Check temperature rise, airflow, and combustion analysis.

CAUTION! Never bypass safety controls. Always verify proper operation before leaving installation.

Specifications

Heating Capacity: 40,000 to 120,000 BTU/h models available
Efficiency: 80% to 96% AFUE depending on model
Electrical: 120V AC, 60Hz, 15 amp circuit
Gas Type: Natural gas or propane (conversion kit required)
Blower Motor: Variable-speed ECM
Heat Exchanger: Stainless steel primary and secondary

Venting: PVC pipe (2" or 3" diameter)

Dimensions: Varies by model (typically 21"W x 21"D x 45"H)

Warranty: Limited lifetime heat exchanger, 10-year parts

Controls and Settings

Integrated control board with diagnostic capabilities and user-adjustable settings.

Control Board: POWER switch, diagnostic LED lights, dip switch settings, terminal strip for thermostat connections.

Thermostat Settings: HEAT/COOL/OFF mode, temperature setpoint, fan AUTO/ON. Control Board DIP Switches: Heat staging, blower delays, accessory configuration. Diagnostic Lights: Flash codes for troubleshooting (1 flash = normal, multiple flashes = error codes).

Connecting Thermostat

Standard thermostat connections using 18-gauge low-voltage wiring.

Turn off power to furnace before connecting thermostat wires.

Connect wires to control board terminal strip: R (24V power), W (heat), G (fan), C (common).

For multi-stage systems: Additional W2, Y1, Y2 terminals for second stage heating/cooling.

Verify proper thermostat operation after power restoration.

Tip: Use color-coded thermostat wire for easy identification and proper connections.

Operating Procedures

Normal heating operation and seasonal startup/shutdown procedures.

Seasonal startup: Turn on gas supply, restore electrical power, set thermostat to desired temperature.

Normal operation: Furnace will cycle automatically based on thermostat demand.

Fan operation: AUTO mode runs blower during heating cycles; ON mode provides continuous airflow.

Seasonal shutdown: Turn off gas supply, turn off electrical power, close gas valve.

Emergency shutdown: Turn off gas supply and electrical power immediately if unsafe condition detected.

WARNING! Never operate furnace without proper venting and combustion air. Carbon monoxide hazard exists if improperly installed or maintained.

Maintenance Schedule

Regular maintenance requirements for optimal performance and safety.

Frequency Maintenance Task

Monthly Check and replace air filter if dirty

Annually Professional inspection and cleaning

Annually Check heat exchanger for cracks

Annually Clean burners and ignition system

Annually Verify gas pressure and combustion

Annually Check vent system for obstructions

Annually Lubricate blower motor if required

Annually Check safety controls operation

Care & Cleaning

Turn off power before performing any cleaning. Use soft brush and vacuum for dust removal.

CAUTION! Never use water or liquid cleaners on electrical components. Keep combustion area clean and free of debris.

Regulatory Information

UL listed and ANSI certified for safety standards. Complies with ASHRAE 90.1 energy efficiency requirements. Manufactured to meet DOE energy conservation standards. For technical support, contact Goodman Manufacturing at 1-877-466-8626 or visit www.goodmanmfg.com.

Troubleshooting

Symptom Possible Cause Corrective Action

Furnace won't start Power, thermostat, safety switch Check circuit breaker, thermostat settings, door switch

No heat Gas supply, ignition, pressure switch Verify gas valve on, check for ignition failure, clear vent obstruction

Short cycling Dirty filter, high limit Replace air filter, check for restricted airflow

Blower won't run Motor, capacitor, control board Check for motor failure, replace capacitor, verify control signal

Gas odor Gas leak Immediately shut off gas supply, evacuate area, call professional

Reset Procedure: Turn off power for 30 seconds, then restore power to reset control board.

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

Goodman Forced Air Furnace Manual © - All Rights Reserved 2025

Frequency	Maintenance Task
Monthly	Check and replace air filter if dirty
Annually	Professional inspection and cleaning
Annually	Check heat exchanger for cracks
Annually	Clean burners and ignition system
Annually	Verify gas pressure and combustion
Annually	Check vent system for obstructions
Annually	Lubricate blower motor if required
Annually	Check safety controls operation

Symptom	Possible Cause	Corrective Action
Furnace won't start	Power, thermostat, safety switch	Check circuit breaker, thermostat settings, door switch
No heat	Gas supply, ignition, pressure switch	Verify gas valve on, check for ignition failure, clear vent obstruction
Short cycling	Dirty filter, high limit	Replace air filter, check for restricted airflow
Blower won't run	Motor, capacitor, control board	Check for motor failure, replace capacitor, verify control signal
Gas odor	Gas leak	Immediately shut off gas supply, evacuate area, call professional