Carrier Infinity 96 Furnace Service Manual

The Carrier Infinity 96 Furnace is a high-efficiency gas furnace featuring variable-speed technology, modulating gas valve, two-stage heating operation, advanced diagnostics, and compatibility with Carrier's Infinity System Control. With up to 96% AFUE efficiency, this furnace provides quiet, consistent heating with precise temperature control. Below are key sections for safety, features, installation, setup, operation, and troubleshooting.

Features at a Glance

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

Installation

Unpack and inspect all components. Ensure proper clearances and venting requirements.

1. Position furnace: Place on stable, level surface with proper clearances (1-inch minimum from combustible materials).
2. Install venting: Use approved PVC piping for intake and exhaust vents.
3. Connect gas supply: Use black iron pipe with proper thread sealant.
4. Electrical connections: Connect 120V power supply and thermostat wiring.
5. Drain connections: Install condensate drain line with proper slope.

WARNING! Gas furnaces produce carbon monoxide; ensure proper venting. Only qualified technicians should perform installation.

First-Time Setup

Power on furnace; follow startup sequence and verify proper operation.

1. Gas pressure adjustment: Set manifold pressure per specifications (3.5" WC natural gas).
2. Blower speed settings: Configure cooling and heating speeds per application requirements.
3. Thermostat configuration: Program Infinity Control for optimal operation.
4. System checkout: Verify proper ignition sequence, flame detection, and safety controls.
5. Combustion analysis: Measure flue gases for proper CO levels and efficiency.

CAUTION! Verify gas connections for leaks using bubble solution. Never use open flame to check for leaks.

Specifications

• Model Series: Carrier Infinity 96
• AFUE Rating: Up to 96%
• Heating Capacity: 40,000 to 120,000 BTU/H
• Stages: Two-stage heating operation
• Blower Type: Variable-speed ECM motor
• Gas Type: Natural gas or LP (with conversion kit)
• Voltage: 120V AC, 60Hz
• Venting: PVC pipe (2-inch minimum)
• Sound Level: As low as 65 dBA
• Warranty: Limited lifetime heat exchanger, 10-year parts

Controls and Settings

Access control board via front panel. Diagnostic LED displays error codes. Infinity Control provides advanced system management.

Control Board: POWER switch, Diagnostic LED, DIP switches, terminal strip.

Heating Settings: Two-stage operation, blower speeds, temperature rise adjustment. Fan Settings: Continuous fan operation, timed off-delay. Safety Controls: Limit switches, pressure switches, flame rollout switches. Diagnostics: LED flash codes for troubleshooting, system status monitoring.

Connecting Components

Gas supply: Black iron pipe with sediment trap. Electrical: 120V power, thermostat connections. Venting: PVC intake and exhaust. Drain: Condensate removal system.

1. Turn off gas and electrical power before making connections.
2. Use proper pipe size for gas supply (½-inch minimum).
3. Ensure vent pipes slope back toward furnace for drainage.
4. Verify thermostat wiring matches control board terminals.

Tip: Always use two wrenches when making gas connections to prevent twisting pipes.

Operating Procedures

Normal heating cycle operation and system sequencing.

1. Call for heat: Thermostat signals furnace to begin heating cycle.
2. Prepurging: Blower operates to clear combustion chamber.
3. Ignition sequence: Hot surface igniter glows, gas valve opens.
4. Flame establishment: Flame sensor confirms ignition.
5. Heating operation: Modulating gas valve adjusts flame, blower circulates warm air.
6. Shutdown: Gas valve closes, blower continues for post-purge cooling.
7. Stage operation: System operates in low stage for mild weather, high stage for cold conditions.

WARNING! Never bypass safety controls. If furnace fails to operate properly, shut off power and gas, then call for service.

Diagnostic Features

LED error codes: Flash patterns indicate specific issues. Infinity Control diagnostics: Advanced system monitoring and fault reporting.

Maintenance & Cleaning

Annual maintenance required for optimal performance and safety.

1. Clean or replace air filter monthly during heating season.
2. Inspect burners and heat exchanger for corrosion or damage.
3. Clean flame sensor with fine sandpaper or steel wool.
4. Check condensate drain system for clogs.
5. Verify vent system is clear and properly sloped.
6. Lubricate blower motor if required (most ECM motors are sealed).

CAUTION! Turn off electrical power and gas supply before performing maintenance. Only qualified technicians should service gas components.

Regulatory Information

ANSI Z21.47: Certified for natural gas and LP operation. UL 795: Commercial-industrial gas heating equipment. Meets ASHRAE 90.1 energy efficiency standards. For technical support, contact Carrier Corporation at 1-800-CARRIER or visit www.carrier.com. Manufactured by Carrier Corporation, Farmington, CT.

Troubleshooting

Reset Procedure: Turn off power for 30 seconds, then restore power to reset control board.

Service: 1-800-CARRIER; www.carrier.com