Lennox G10 Furnace Manual

The Lennox G10 Furnace is a high-efficiency gas furnace designed for residential heating applications. This 90% AFUE furnace features a durable heat exchanger, electronic ignition, variable-speed blower motor, and comprehensive safety controls. Suitable for installation in upflow, downflow, or horizontal configurations. Below are key sections for safety, features, installation, operation, maintenance, and troubleshooting.

Features at a Glance

Key components: Duralok™ heat exchanger, variable-speed blower motor, hot surface ignition, pressure switches, flame sensor, limit controls.

Installation Requirements

Professional installation required. Ensure proper clearances and local code compliance.

1. Location: Install in dry, clean area with adequate service clearance.
2. Combustion Air: Provide adequate fresh air supply per local codes.
3. Venting: Use approved PVC pipe for intake and exhaust.
4. Gas Supply: Connect to proper gas line with sediment trap.
5. Electrical: Connect to 120V AC power with proper grounding.
6. Ductwork: Ensure proper sizing and sealing.

WARNING! Gas appliances can be dangerous if improperly installed. Use qualified HVAC technician.

First-Time Setup

Initial startup must be performed by qualified technician.

1. Verify all connections: Gas, electrical, venting, and air ducts.
2. Check gas pressure: Adjust manifold pressure if necessary.
3. Test safety controls: Verify limit switches and pressure sensors.
4. Program thermostat: Set up heating cycles and fan operation.
5. Commission system: Run through complete heating cycle.

CAUTION! Never bypass safety controls. Ensure proper ventilation.

Specifications

• Model Series: G10Q, G10U, G10X
• AFUE: 90%
• Input BTU/h: 40,000 - 120,000 (varies by model)
• Output BTU/h: 36,000 - 108,000 (varies by model)
• Gas Type: Natural Gas
• Electrical: 120V AC, 60Hz
• Blower Motor: Variable-speed ECM
• Venting: 2" PVC recommended
• Sound Level: As low as 65 dBA
• Warranty: 20-year heat exchanger, 5-year parts

Controls and Settings

Integrated control board with diagnostic LED. Access via front panel cover.

Control Board: LED status light, dip switches for configuration, reset button.

Thermostat Connections: R, W, G, Y, C terminals. Blower Settings: Adjustable fan speeds for heating and continuous operation. Limit Controls: Auto-reset high limit switches. Pressure Switches: Verify proper venting operation. Gas Valve: Modulating control for precise heating.

Venting and Combustion Air

PVC venting system for intake and exhaust.

1. Vent Pipe: Use Schedule 40 PVC, CPVC, or approved ABS.
2. Termination: Locate away from windows, doors, and air intakes.
3. Slope: Pitch pipes slightly downward toward furnace.
4. Clearances: Maintain required distances from combustible materials.
5. Combustion Air: Provide adequate fresh air supply per installation manual.

Tip: Always check local building codes for venting requirements.

Operation Instructions

Normal operation through connected thermostat.

1. Set thermostat to desired temperature.
2. Furnace will initiate heating cycle when temperature drops below setpoint.
3. Inducer motor starts first to establish draft.
4. Hot surface igniter heats up.
5. Gas valve opens, burner ignites.
6. Blower motor starts after heat exchanger warms up.
7. Cycle continues until thermostat satisfaction.

WARNING! Never operate without proper venting and combustion air.

Maintenance Procedures

Regular maintenance ensures optimal performance and safety.

1. Monthly: Check and replace air filter as needed.
2. Annual: Professional inspection and cleaning.
3. Burner Inspection: Clean burners and check flame pattern.
4. Heat Exchanger: Visual inspection for cracks or damage.
5. Venting: Check for obstructions and proper slope.
6. Electrical: Check connections and component operation.

CAUTION! Turn off power and gas supply before servicing.

Safety Features

Multiple safety systems protect against hazardous conditions.

Regulatory Information

UL listed and ANSI certified. Complies with applicable safety standards. Natural gas appliance must be installed in accordance with National Fuel Gas Code (NFPA 54/ANSI Z223.1) and local building codes. Manufactured by Lennox Industries Inc. For technical support, contact Lennox at 1-800-9-LENNOX or visit www.lennox.com.

Troubleshooting

Reset: Turn power off for 30 seconds, then restore.

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