Goodman 90 Furnace Installation Manual

The Goodman 90 Furnace is a high-efficiency gas furnace designed for residential heating applications with 90% AFUE rating, multi-speed blower motor, electronic ignition system, durable heat exchanger, integrated diagnostic controls, safety shut-off features, and compatibility with standard venting systems. Suitable for installation in various climate zones and designed for reliable performance with natural gas or propane. Below are key sections for safety, features, installation, setup, operation, and troubleshooting.

Features at a Glance

Key components: High-efficiency heat exchanger, multi-speed blower, electronic ignition, integrated control board, pressure switches, flame sensor, gas valve, venting connections.

Installation Requirements

Verify local codes and obtain necessary permits before installation.

1. Location: Install in dry, level area with adequate clearance for service access.
2. Combustion Air: Ensure adequate fresh air supply for proper combustion.
3. Venting: Plan PVC vent routing with proper slope and termination clearances.
4. Gas Supply: Verify gas type and pressure requirements.
5. Electrical: Dedicated 120V circuit required with proper grounding.

WARNING! Installation must be performed by qualified HVAC technician. Gas furnaces can produce carbon monoxide - ensure proper venting.

Installation Procedures

Follow step-by-step installation sequence for proper operation.

1. Position furnace: Place on level surface with proper clearances.
2. Install venting: Connect PVC intake and exhaust pipes with proper slope.
3. Connect gas line: Use approved pipe compound and leak test all connections.
4. Electrical wiring: Connect line voltage and low-voltage thermostat wires.
5. Duct connections: Secure supply and return air ducts properly.
6. Final checks: Verify all connections, install filter, and perform start-up procedure.

CAUTION! Always disconnect power and gas supply before servicing. Use proper personal protective equipment.

Specifications

• AFUE Rating: 90% Annual Fuel Utilization Efficiency
• Input BTU/H: 40,000 - 120,000 (varies by model)
• Gas Type: Natural gas or propane (conversion kit required)
• Electrical: 120V, 60Hz, 15A circuit
• Blower Motor: Multi-speed ECM motor
• Venting: 2" PVC pipe for intake and exhaust
• Operating Temp Range: -30°F to 150°F ambient
• Sound Rating: Standard residential noise levels
• Warranty: Limited lifetime heat exchanger, 10-year parts

Controls and Settings

Integrated control board with diagnostic LED and DIP switch settings.

Control Board: LED flash codes for diagnostics, DIP switches for blower speeds, gas type selection, accessory configuration.

Thermostat Connections: R (24V), C (Common), W (Heat), G (Fan), Y (Cool). Blower Settings: HEAT ON delay, COOL ON delay, continuous fan speed. Gas Pressure: Factory set for natural gas, adjustable for propane. Limit Switches: Automatic high-temperature cut-off. Pressure Switches: Verify proper venting operation.

Electrical Connections

Proper electrical wiring is critical for safe operation.

1. Disconnect power at main breaker before wiring.
2. Connect 120V power to designated line voltage terminals.
3. Connect thermostat wires to low-voltage terminal block.
4. Verify proper grounding of all electrical components.
5. Check polarity and voltage before energizing unit.

Tip: Use copper conductors only. Follow NEC and local electrical codes.

Gas Line Connections

Gas piping must be properly sized and leak-tested.

1. Install manual shut-off valve within 6 feet of furnace.
2. Use black iron pipe or approved flexible connector.
3. Apply pipe compound to male threads only.
4. Pressure test at 14" WC for 10 minutes - no pressure drop.
5. Check gas pressure at manifold with manometer.
6. Verify proper flame characteristics during ignition.

WARNING! Gas leaks can cause explosion or fire. Always use leak detection solution on all connections.

Venting Requirements

PVC vent system must comply with manufacturer specifications and local codes.

1. Use Schedule 40 PVC pipe for intake and exhaust.
2. Maintain 1/4" per foot slope back to furnace.
3. Terminate vents with proper clearances from windows, doors, and air intakes.
4. Secure all joints with PVC cement.
5. Install bird screens on termination caps.

CAUTION! Improper venting can cause carbon monoxide poisoning. Never use single-wall metal vent pipe.

Maintenance & Service

Regular maintenance ensures optimal performance and safety.

Replace air filter monthly during heating season. Annual professional inspection recommended. Clean flame sensor and burners as needed. Check vent system for obstructions. Verify condensate drain is clear.

CAUTION! Always disconnect power before servicing. Only qualified technicians should perform internal repairs.

Regulatory Information

UL listed and ANSI certified for safety standards. Complies with Department of Energy efficiency requirements. Installation must meet National Fuel Gas Code NFPA 54 and local building codes. For technical support, contact Goodman Manufacturing at 1-877-466-8626 or visit www.goodmanmfg.com.

Troubleshooting

Reset: Power cycle unit to clear temporary fault codes.

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