Lennox Elite Series G23 Furnace Manual

The Lennox Elite Series G23 Furnace is a high-efficiency gas furnace designed for residential heating applications. Featuring advanced combustion technology, variable-speed blower motor, and durable construction, this furnace provides reliable warmth with energy-saving performance. 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. Specifications 5. Controls and Settings 6. Venting and Combustion Air 7. Operation Instructions 8. Maintenance Procedures 9. Care & Cleaning 10. Regulatory Information 11. Troubleshooting

Features at a Glance

Key components: Durable heat exchanger, variable-speed blower motor, electronic ignition system, multi-speed inducer motor, integrated control board.

Feature	Description
Heat Exchanger	Stainless steel construction for durability and efficiency
Blower Motor	Variable-speed ECM motor for quiet operation
Ignition System	Hot surface ignition for reliable startup
Inducer Motor	Multi-speed for proper venting
Control Board	Integrated microprocessor for system control
Gas Valve	Modulating for precise temperature control
Air Filter	Standard 1-inch or 4-inch media filter compatible
Pressure Switches	Safety switches for proper venting
Limit Switches	High-temperature safety protection
Flame Sensor	Ensures proper burner operation

Installation Requirements

Professional installation required. Verify local codes and obtain permits.

Location: Install in dry, clean area with proper clearances.
Venting: Follow manufacturer specifications for vent pipe sizing and routing.
Gas Supply: Proper gas line sizing and pressure requirements.
Electrical: 120V AC power supply with proper grounding.
Ductwork: Properly sized and sealed duct system.

WARNING! Gas furnaces produce carbon monoxide. Proper installation and venting are critical for safety. Only qualified technicians should install this equipment.

First-Time Setup

Initial startup must be performed by qualified technician.

Verify installation: Check all connections, clearances, and venting.
Gas pressure: Adjust gas valve to specified manifold pressure.
Electrical: Verify proper voltage and polarity.
Blower speed: Set appropriate CFM for heating application.
System check: Test all safety controls and operational sequences.

CAUTION! Never operate furnace without proper venting. Ensure combustion air requirements are met.

Specifications

Input Capacity: 40,000 to 120,000 BTU/hr (model dependent)
AFUE Rating: Up to 96% efficiency
Gas Type: Natural gas (LP conversion kit available)
Electrical: 120V AC, 60Hz
Blower Motor: Variable-speed ECM
Sound Level: As low as 65 dBA
Venting: PVC pipe compatible
Warranty: Limited lifetime heat exchanger warranty
Dimensions: Varies by model (check specific model data)

Controls and Settings

Integrated control board with LED status lights. Thermostat controls system operation.

Control Board LEDs: Green - normal operation, Red - fault condition, Yellow - status indicator.

Thermostat Settings: Heat/Cool/Auto modes, Fan On/Auto, Temperature setpoints. Blower Speeds: Adjustable for heating and continuous fan operation. Gas Valve: Modulating control for precise temperature maintenance.

Venting and Combustion Air

Direct vent or conventional venting options available.

Direct Vent: Use PVC pipe for intake and exhaust.
Conventional Vent: Metal B-vent for vertical applications.
Combustion Air: Provide adequate fresh air supply.
Clearances: Maintain proper clearances to combustibles.

Tip: Always follow local codes and manufacturer specifications for venting requirements.

Operation Instructions

Normal operation controlled by thermostat.

Set thermostat to desired temperature in HEAT mode.
Furnace will initiate startup sequence when heat is called.
Inducer motor starts first to establish draft.
Hot surface igniter heats up and gas valve opens.
Burners ignite and blower starts after heat exchanger warms.
System cycles off when thermostat setpoint is reached.

WARNING! If you smell gas, immediately turn off gas supply and call qualified service technician.

Maintenance Procedures

Regular maintenance ensures optimal performance and safety.

Monthly: Check and replace air filter as needed.
Annual: Professional inspection and cleaning.
Burner inspection: Clean and verify proper flame pattern.
Heat exchanger: Visual inspection for cracks or damage.
Venting: Check for obstructions and proper operation.

Care & Cleaning

Keep furnace area clean and free of combustible materials.

CAUTION! Turn off power and gas supply before cleaning. Use soft brush and vacuum for cleaning components. Never use water or liquid cleaners on electrical components.

Regulatory Information

UL listed and ANSI certified. Complies with applicable safety standards. Manufactured to meet or exceed industry standards for residential gas furnaces. For technical support, contact Lennox at 1-800-9-LENNOX or visit www.lennox.com.

Troubleshooting

Symptom	Possible Cause	Corrective Action
Furnace won't start	Power/thermostat	Check circuit breaker; verify thermostat settings; check door switch.
No heat	Gas supply/ignition	Verify gas valve on; check pilot/igniter; call for service if needed.
Short cycling	Airflow/filter	Replace dirty filter; check for blocked vents; verify proper airflow.
Blower won't stop	Thermostat/fan limit	Check thermostat fan setting; inspect fan limit control.
Unusual noises	Mechanical issues	Check for loose components; inspect blower wheel; call for service.

Reset: Turn power off for 30 seconds then restore. Check LED fault codes on control board.

Service: 1-800-9-LENNOX; www.lennox.com