Ducane Furnace Repair Manual

The Ducane Furnace is a high-efficiency heating system designed for residential and light commercial applications. This manual covers various Ducane furnace models with features including electronic ignition, variable-speed blowers, multiple heat stages, diagnostic LED indicators, and compatibility with standard thermostats. Below are key sections for safety, features, installation, troubleshooting, maintenance, and technical specifications.

1. Features at a Glance 2. Installation Guidelines 3. Initial Setup 4. Technical Specifications 5. Controls and Operation 6. Maintenance Procedures 7. Diagnostic Codes 8. Safety Features 9. Cleaning & Care 10. Regulatory Information 11. Troubleshooting Guide

Features at a Glance

Key components: Heat exchanger, blower assembly, gas valve, igniter, flame sensor, pressure switches, control board, and diagnostic LED.

Feature	Description
Heat Exchanger	Stainless steel construction for durability and efficiency
Blower Assembly	Variable-speed ECM motor for quiet operation
Gas Valve	Multi-stage gas control for precise heating
Igniter System	Hot surface igniter for reliable ignition
Flame Sensor	Safety feature to detect flame presence
Pressure Switches	Verify proper venting operation
Control Board	Microprocessor-based control system
Diagnostic LED	Flashing codes for troubleshooting
Thermostat Connections	Standard 24V connections
Filter System	Standard 1-inch or 4-inch media filters

Installation Guidelines

Unpack and inspect all components. Ensure proper clearances and ventilation.

Location selection: Choose well-ventilated area with proper clearances (typically 1 inch sides, 6 inches top).
Gas line connection: Use approved gas piping materials; pressure test for leaks.
Electrical wiring: Connect 120V power supply and thermostat wiring per local codes.
Vent system: Install approved PVC vent pipes with proper slope and termination.
Drain line: Connect condensate drain to proper disposal point.

WARNING! Gas appliances can be dangerous; only qualified technicians should perform installation. Ensure proper ventilation to prevent carbon monoxide hazards.

Initial Setup

Power on furnace; follow startup sequence.

System check: Verify gas supply, electrical power, and thermostat settings.
Initial ignition: System will perform self-check and attempt ignition.
Blower operation: Verify blower starts and operates at correct speeds.
Temperature verification: Check supply air temperatures within specified range.
Safety checks: Confirm all safety switches and limits are functioning.

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

Technical Specifications

Heating Capacity: 40,000 - 120,000 BTU/h depending on model
Efficiency Rating: 80% - 96% AFUE
Electrical Requirements: 120V AC, 60Hz
Gas Type: Natural gas or LP (conversion kit required)
Gas Pressure: Natural gas: 3.5" WC; LP: 10" WC
Blower Motor: ECM variable speed
Airflow: 600 - 1600 CFM depending on model
Vent Material: PVC, CPVC, or ABS
Operating Temp Range: -30°F to 120°F ambient
Warranty: Limited lifetime heat exchanger, 10 years parts

Controls and Operation

Access control board via front panel. LED indicator shows system status.

Thermostat Connections: R (24V), C (Common), W (Heat), G (Fan), Y (Cool)

Operating Modes: Heating cycle, fan only, standby. Control Board: Diagnostic LED flashes codes for troubleshooting. Gas Valve: Multi-stage operation for efficiency. Blower Control: Variable speed operation with ramp-up profiles. Limit Switches: High temperature safety cut-off. Pressure Switches: Verify inducer operation and venting.

Maintenance Procedures

Regular maintenance ensures optimal performance and safety.

Monthly filter check: Inspect and replace dirty filters.
Annual professional service: Complete system inspection and cleaning.
Blower cleaning: Remove dust and debris from blower assembly.
Heat exchanger inspection: Check for cracks or corrosion.
Vent system: Verify clear and unobstructed.
Electrical connections: Tighten all terminals.
Gas line: Check for leaks with approved detector.

Tip: Keep area around furnace clear of combustible materials.

Diagnostic Codes

LED flash patterns indicate system status and faults.

Flash Pattern	Description	Action
1 Flash	Normal operation	No action required
2 Flashes	Pressure switch error	Check venting, inducer
3 Flashes	Ignition failure	Check gas, igniter, flame sensor
4 Flashes	Limit switch open	Check airflow, filter
5 Flashes	Flame sensed when off	Check gas valve, control board
6 Flashes	Blower error	Check motor, capacitor
7 Flashes	Rollout switch open	Check heat exchanger, venting

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
Flame sensor: Confirms burner ignition
Gas valve: Automatic shutoff on system fault
Control board diagnostics: Continuous system monitoring

WARNING! Never disable safety devices. Replace faulty components immediately.

Cleaning & Care

Turn off power and gas supply before cleaning. Use soft brush and vacuum for dust removal.

CAUTION! Do not use water or liquid cleaners. Keep electrical components dry. Wear protective equipment when handling fiberglass insulation.

Regulatory Information

UL listed and ANSI certified for safety standards. Complies with Department of Energy efficiency requirements. Manufactured to meet or exceed industry standards for residential gas furnaces. Copyright © Ducane Heating & Cooling. For technical support, visit www.ducanehvac.com or contact 1-800-ducane-hvac.

Troubleshooting Guide

Symptom	Possible Cause	Corrective Action
Furnace won't start	Power, thermostat, door switch	Check circuit breaker, thermostat settings, door switch engagement
No heat	Gas supply, igniter, flame sensor	Verify gas valve on, check igniter operation, clean flame sensor
Short cycling	Filter, airflow, limit switch	Replace filter, check vents, test limit switch
Blower won't run	Motor, capacitor, control board	Check motor operation, test capacitor, verify control signals
Unusual noises	Blower, inducer, heat exchanger	Inspect blower wheel, inducer motor, check for heat exchanger cracks
Pilot/ignition issues	Gas pressure, igniter, sensor	Check gas pressure, test igniter voltage, clean flame sensor

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

Service: 1-800-ducane-hvac; www.ducanehvac.com