Lennox Elite Series G26 Furnace Manual

The Lennox Elite Series G26 is a high-efficiency gas furnace featuring variable-speed technology, two-stage gas valve operation, durable heat exchanger construction, quiet operation, and advanced diagnostic capabilities. With AFUE ratings up to 96.7%, this furnace provides reliable heating performance while optimizing energy consumption. Below are key sections covering safety, features, installation, operation, maintenance, and troubleshooting.

Features at a Glance

Key components: Variable-speed blower motor, two-stage gas valve, durable aluminized steel heat exchanger, integrated control board, pressure switches, flame sensor, and igniter.

Installation Requirements

Proper installation is critical for safe and efficient operation. Follow all local codes and manufacturer guidelines.

1. Location selection: Install in dry, clean area with adequate clearance for service access.
2. Venting: Use approved PVC piping for direct vent installation; maintain proper slope.
3. Gas connection: Use black iron pipe with proper thread sealant; pressure test all connections.
4. Electrical: Connect to dedicated 120V circuit; proper grounding required.
5. Ductwork: Ensure proper sizing and sealing for optimal airflow.

WARNING! Installation must be performed by qualified HVAC technician. Improper installation can cause fire, explosion, or carbon monoxide poisoning.

Initial Setup & Startup

Professional startup procedure ensures proper operation and warranty validation.

1. Verify installation: Check all connections, clearances, and venting.
2. Gas pressure adjustment: Set manifold pressure per specifications on rating plate.
3. Electrical connections: Verify proper voltage and grounding.
4. Blower settings: Adjust dip switches for proper airflow based on installation.
5. System check: Test ignition sequence, safety controls, and temperature rise.
6. Customer orientation: Explain thermostat operation and basic maintenance.

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

Technical Specifications

• Model Series: G26
• AFUE Rating: Up to 96.7%
• Input BTU/H: 40,000 - 120,000 (varies by model)
• Stages: Two-stage heating
• Blower Type: Variable-speed ECM
• Voltage: 120V, 60Hz
• Gas Type: Natural gas (LP conversion kit available)
• Venting: PVC direct vent (2" or 3")
• Sound Level: As low as 65 dBA
• Warranty: 20-year heat exchanger, 5-year parts

Controls and Operation

Integrated furnace control board manages all operations with diagnostic capabilities.

Thermostat Requirements: Compatible with most 24V thermostats; for full functionality use Lennox iComfort thermostat.

Operation Modes: Two-stage heating provides low-fire for mild weather and high-fire for extreme cold. Variable-speed blower adjusts airflow for optimal comfort and efficiency. Diagnostic LED flashes error codes during fault conditions.

Settings: Dip switches for blower speeds, temperature rise adjustments, venter motor delay settings.

Venting and Combustion Air

Direct vent system uses separate pipes for combustion air intake and flue gas exhaust.

1. Vent pipe installation: Use schedule 40 PVC; maintain 1/4" per foot slope toward furnace.
2. Termination: Locate vents at least 12 inches above ground level and away from windows.
3. Combustion air: Ensure adequate fresh air supply for proper combustion.
4. Pipe length: Follow manufacturer guidelines for maximum vent run.

Tip: Regularly inspect vent terminations for blockages from snow, leaves, or debris.

Maintenance Procedures

Regular maintenance ensures efficiency, reliability, and longevity.

1. Monthly: Check air filter; replace when dirty (typically 1-3 months).
2. Annual professional service: Includes combustion analysis, heat exchanger inspection, blower cleaning, and safety check.
3. Seasonal: Inspect vent system, check drain lines, verify thermostat operation.
4. Component inspection: Flame sensor cleaning, pressure switch verification, igniter check.
5. Airflow verification: Ensure proper static pressure and temperature rise.

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

Safety Features

Multiple safety systems protect against hazardous conditions.

Flame Rollout Switches: Detect improper burner operation. High Limit Switches: Prevent overheating. Pressure Switches: Verify proper venting operation. Ignition Control: Monitors flame presence. Gas Valve: Automatic shutoff during faults.

Care & Cleaning

Keep furnace area clean and unobstructed.

Exterior: Wipe with damp cloth only. Interior: Professional cleaning only. Filter: Replace regularly with proper size and type. Burners: Professional cleaning only. Blower: Professional cleaning and lubrication.

CAUTION! Never use water, solvents, or abrasive cleaners on furnace components.

Regulatory Information

UL certified for safety. ANSI Z21.47 compliant. Meets DOE efficiency standards. Manufactured to comply with U.S. safety and performance requirements. For technical support, contact Lennox Industries Inc. or visit www.lennox.com. Installation must comply with National Fuel Gas Code (NFPA 54) and local building codes.

Troubleshooting

Reset: Turn power off for 30 seconds, then restore. If problem persists, call for service.

Service: Contact authorized Lennox dealer for all repairs. 1-800-9-LENNOX; www.lennox.com