Luxaire Furnace Manual GM9S

The Luxaire GM9S is a high-efficiency gas furnace series with AFUE ratings up to 97%, featuring variable-speed ECM blower motors, two-stage gas valve operation, durable aluminized steel heat exchangers, quiet operation, diagnostic LED lights, and compatibility with various thermostat systems. Below are key sections for safety, features, installation, operation, maintenance, and troubleshooting.

1. Features at a Glance 2. Installation Requirements 3. First-Time Setup 4. Technical Specifications 5. Controls and Operation 6. Venting and Combustion Air 7. Maintenance Procedures 8. Safety Features 9. Care & Cleaning 10. Regulatory Information 11. Troubleshooting

Features at a Glance

Key components: Two-stage gas valve, ECM variable-speed blower motor, aluminized steel primary and secondary heat exchangers, diagnostic LED system, pressure switches, flame sensor, and hot surface ignitor.

Feature	Description
Two-stage gas valve	Provides efficient heating at low and high fire rates
ECM blower motor	Variable-speed operation for quiet, efficient airflow
Heat exchangers	Aluminized steel construction for durability
Diagnostic LED	Flashing codes for troubleshooting
Pressure switches	Ensures proper venting operation
Flame sensor	Monitors burner flame presence
Hot surface ignitor	Reliable electronic ignition system
Gas connection	1/2" NPT gas inlet
Electrical connection	120V AC, 60Hz power supply
Thermostat connection	Compatible with most 24V systems

Installation Requirements

Unpack and inspect all components. Ensure proper location with adequate clearance.

Location requirements: Minimum 24" front clearance, 6" sides, 6" rear, 24" top.
Gas connection: Use approved gas pipe; pressure test for leaks.
Electrical wiring: Connect to 120V AC power; proper grounding required.
Venting system: Install PVC vent pipes per local codes.
Combustion air: Provide adequate fresh air supply.

WARNING! Gas furnaces produce carbon monoxide; proper venting is critical. Installation must comply with local codes.

First-Time Setup

Power on furnace; follow startup sequence.

Gas pressure adjustment: Set manifold pressure per specifications.
Blower speed settings: Adjust dip switches for heating CFM requirements.
Thermostat wiring: Connect R, W, G, C terminals as needed.
System check: Verify proper ignition sequence and flame.
Airflow verification: Check static pressure and temperature rise.

CAUTION! Only qualified HVAC technicians should perform installation and setup.

Technical Specifications

AFUE Rating: Up to 97% efficiency
Input BTU/H: 40,000 to 120,000 (varies by model)
Stages: Two-stage heating operation
Blower Type: ECM variable-speed
Heat Exchanger: Aluminized steel primary and secondary
Ignition: Hot surface direct ignition
Venting: PVC pipe (2" or 3" depending on model)
Gas Type: Natural gas (LP conversion kits available)
Electrical: 120V AC, 60Hz
Dimensions: Varies by model (typically 21"W x 21"D x 40"H)

Controls and Operation

Integrated furnace control board manages all operations. Access door switch must be engaged for operation.

Control Board: Monitors safety devices, controls ignition sequence, manages blower operation, provides diagnostic codes.

Operation Modes: Standby (waiting for heat call), Prepurge (blower on), Ignition (hot surface ignitor on), Flame Proving (flame sensor verification), Main Burner Operation (gas valve open), Postpurge (blower continues after heat cycle).

Venting and Combustion Air

Direct vent system using PVC pipes. Combustion air intake and exhaust vent required.

Vent pipe sizing: Use manufacturer-specified diameters.
Pipe length limits: Follow maximum vent run specifications.
Termination clearance: Maintain proper distance from windows and openings.
Combustion air: Ensure adequate fresh air supply per installation requirements.

Tip: Always check vent pipes for obstructions before operation.

Maintenance Procedures

Annual maintenance recommended for optimal performance.

Filter replacement: Change every 1-3 months depending on usage.
Heat exchanger inspection: Check for cracks or corrosion annually.
Blower cleaning: Vacuum blower wheel and motor annually.
Flame sensor cleaning: Gently clean with emery cloth annually.
Vent system inspection: Check for obstructions or damage.
Gas pressure verification: Check manifold pressure annually.

WARNING! Turn off power and gas supply before performing any maintenance.

Safety Features

Multiple safety devices protect against hazardous conditions: Flame rollout switches, high limit switches, pressure switches, flame sensor, ignitor control, door safety switch.

Care & Cleaning

Keep furnace area clean and free of combustible materials. Use vacuum with soft brush attachment for cleaning.

CAUTION! Never use water or liquid cleaners on electrical components. Keep filters clean for proper airflow.

Regulatory Information

ANSI Z21.47: Certified for natural gas operation. UL listed. CSA certified. Installation must comply with National Fuel Gas Code (NFPA 54) and local building codes. For support, contact Luxaire customer service at 1-800-572-7225 or visit www.luxaire.com.

Troubleshooting

Symptom	Possible Cause	Corrective Action
Furnace won't start	Power supply/thermostat	Check circuit breaker; verify thermostat settings; ensure door switch engaged.
No heat	Gas supply/ignition	Verify gas valve on; check for ignition lockout; inspect flame sensor.
Blower won't run	Motor/control board	Check blower motor capacitor; verify control board signals; inspect wiring.
Frequent cycling	Filter/limit switch	Replace dirty filter; check high limit switch; verify proper airflow.
Error codes flashing	Various faults	Refer to diagnostic chart in control panel; count LED flashes for code.

Reset: Power cycle furnace to clear temporary lockouts.

Service: 1-800-572-7225; www.luxaire.com