Carrier Furnace Repair Manuals

Carrier furnaces are high-efficiency heating systems designed for residential and commercial use, featuring advanced technology for optimal performance and energy savings. These repair manuals cover various Carrier furnace models including Infinity, Performance, and Comfort series, with troubleshooting guides, maintenance procedures, safety protocols, and technical specifications for professional technicians and DIY enthusiasts.

1. Safety Precautions 2. Common Models Overview 3. Diagnostic Procedures 4. Technical Specifications 5. Error Code Interpretation 6. Component Replacement 7. Maintenance Schedule 9. Wiring Diagrams 10. Parts List 11. Warranty Information 12. Troubleshooting Guide

Safety Precautions

Essential safety measures before performing any furnace repair or maintenance.

Safety Measure	Description
Power Disconnection	Turn off electrical power at circuit breaker before servicing
Gas Valve Shutoff	Close main gas supply valve before working on gas components
Carbon Monoxide Detection	Install CO detectors near furnace area
Proper Ventilation	Ensure adequate airflow in furnace room
Fire Extinguisher	Keep Class ABC fire extinguisher nearby
Personal Protective Equipment	Wear safety glasses and gloves during repairs
Clear Work Area	Remove flammable materials from furnace vicinity
Professional Assistance	Contact certified technician for complex gas/electrical issues

Common Models Overview

Popular Carrier furnace models and their key characteristics.

Infinity 98: Modulating gas valve, variable-speed blower, up to 98.5% AFUE
Performance 96: Two-stage heating, durable heat exchanger, 96% AFUE
Comfort 92: Single-stage operation, reliable performance, 92% AFUE
WeatherMaker 8000: Compact design, efficient operation
58MCA: Multi-position configuration, quiet operation

WARNING! Always verify model number before ordering parts or performing repairs.

Diagnostic Procedures

Step-by-step troubleshooting process for common furnace issues.

Visual Inspection: Check for obvious damage, leaks, or blockages
Power Check: Verify 120V AC supply to furnace
Thermostat Testing: Confirm thermostat is calling for heat
Ignition Sequence: Observe startup sequence for failures
Gas Pressure Measurement: Check manifold and inlet pressures
Airflow Verification: Ensure proper duct airflow and filter condition
Safety Switch Testing: Test limit switches and pressure switches

CAUTION! Use proper testing equipment and follow manufacturer specifications.

Technical Specifications

Input Capacity: 40,000 to 150,000 BTU/h
Efficiency Ratings: 80% to 98.5% AFUE
Electrical Requirements: 120V AC, 60Hz, 15A circuit
Gas Type: Natural gas or propane (conversion kit required)
Venting: PVC, CPVC, or metal venting depending on model
Blower Motor: Variable-speed or multi-speed ECM/PSC motors
Heat Exchanger: Stainless steel or aluminized steel construction
Dimensions: Varies by model (typically 21"W x 26"D x 45"H)

Error Code Interpretation

Common Carrier furnace error codes and their meanings.

LED Flash Patterns: 1 flash = Limit circuit fault, 2 flashes = Pressure switch fault, 3 flashes = Ignition failure, 4 flashes = Pressure switch stuck closed, 5 flashes = Gas valve circuit fault, 6 flashes = Blower fault, 7 flashes = Rollout switch fault.

Control Board: Check status LED for flash patterns. Refer to specific model manual for exact code interpretation. Reset power after resolving issues to clear error codes.

Component Replacement

Common replacement parts and installation procedures.

Turn off power and gas supply before beginning work
Filter Replacement: Remove old filter, install new one with arrow facing airflow direction
Ignitor Replacement: Disconnect wires, remove mounting screws, install new ignitor
Flame Sensor Cleaning: Remove sensor, clean with emery cloth, reinstall
Pressure Switch Testing: Use multimeter to verify switch operation
Blower Motor Replacement: Disconnect electrical, remove mounting, install new motor
Control Board Replacement: Document wiring, remove old board, install replacement

Tip: Take photos before disassembly for proper reassembly reference.

Maintenance Schedule

Recommended maintenance intervals for optimal furnace performance.

Monthly: Check air filter, replace if dirty
Seasonal: Professional inspection before heating season
Annual: Complete system cleaning and safety check
Every 2-3 Years: Heat exchanger inspection
Every 5 Years: Blower motor lubrication (if required)
As Needed: Duct cleaning and thermostat calibration

WARNING! Only qualified technicians should perform internal component maintenance.

Wiring Diagrams

Standard wiring configurations for Carrier furnace models.

Thermostat Connections: R (24V power), W (Heat), G (Fan), Y (Cooling), C (Common). Furnace Control Board: Follow color-coded wiring per model-specific diagram. High Voltage: Black (Hot), White (Neutral), Green (Ground). Low Voltage: Typically 18-22 gauge thermostat wire.

Parts List

Common replacement parts for Carrier furnaces.

Ignitors: Silicon carbide or hot surface types
Flame Sensors: Universal and model-specific designs
Pressure Switches: Various pressure ratings
Gas Valves: Single-stage, two-stage, and modulating
Blower Motors: ECM and PSC motor types
Control Boards: Furnace-specific circuit boards
Heat Exchangers: Primary and secondary sections
Filters: 1", 4", and 5" media filters

Warranty Information

Carrier furnace warranty coverage and registration requirements.

Standard limited warranty: 20-year heat exchanger, 5-year parts, 1-year labor. Registration must be completed within 90 days of installation for full warranty coverage. Professional installation required for warranty validation. Keep original receipt and installation documentation. For warranty claims, contact Carrier authorized dealers or 1-800-CARRIER.

Troubleshooting Guide

Symptom	Possible Cause	Corrective Action
Furnace won't start	Power issue, thermostat setting	Check circuit breaker, verify thermostat heat setting, ensure gas valve open
No heat output	Ignition failure, gas supply	Check ignitor, gas pressure, flame sensor, pressure switches
Short cycling	Dirty filter, airflow restriction	Replace air filter, check vents and ductwork, verify thermostat location
Blower not working	Motor failure, capacitor issue	Test blower motor, check capacitor, verify control board signals
Unusual noises	Loose components, bearing wear	Tighten mounting hardware, lubricate motor bearings, check blower wheel
Gas odor	Gas leak, incomplete combustion	Immediately shut off gas, ventilate area, contact gas company

Reset Procedure: Turn thermostat to off, wait 30 seconds, turn to heat mode.

Technical Support: 1-800-CARRIER; www.carrier.com/residential