Nordyne Gas Furnace Service Manual

The Nordyne Gas Furnace is a high-efficiency heating system designed for residential use, featuring advanced combustion technology, electronic ignition, variable-speed blower motors, and comprehensive safety controls. This manual covers installation, operation, maintenance, troubleshooting, and service procedures for various Nordyne gas furnace models. Below are key sections for safety, technical specifications, installation, operation, maintenance, and troubleshooting.

1. Safety Precautions 2. Technical Specifications 3. Installation Procedures 4. Electrical Connections 5. Gas Line Connections 6. Venting Requirements 7. Startup and Operation 8. Control System Overview 9. Maintenance Procedures 10. Troubleshooting Guide 11. Parts List and Diagrams

Safety Precautions

Critical safety information for installation, operation, and service of Nordyne gas furnaces.

Hazard Type	Precaution
Gas Leaks	Always check for gas leaks with soap solution; never use open flame
Electrical Shock	Disconnect power before servicing; verify proper grounding
Carbon Monoxide	Ensure proper venting; install CO detectors in living areas
High Temperature	Allow furnace to cool before servicing heat exchanger
Combustion Air	Provide adequate combustion and ventilation air
Flammable Materials	Maintain clearance from combustible materials
Gas Pressure	Verify correct manifold pressure per specifications
Venting	Inspect vent system for obstructions and proper slope

Technical Specifications

Detailed technical data for Nordyne gas furnace models.

Input Capacity: 40,000 - 120,000 BTU/H
Efficiency Rating: 80% - 96% AFUE
Gas Type: Natural Gas or LP Propane
Gas Pressure: Natural Gas: 3.5" WC; LP: 10" WC
Electrical: 120V AC, 60Hz, 15 Amp circuit
Blower Motor: Variable-speed ECM or PSC
Ignition System: Hot surface or intermittent pilot
Venting: Category I or IV depending on model
Dimensions: Varies by model (typically 21"W x 26"D x 45"H)
Weight: 80-150 lbs depending on model

Installation Procedures

Step-by-step installation guidelines for proper furnace setup.

Location Selection: Choose area with adequate clearance and combustion air.
Uncrate and Inspect: Check for shipping damage and verify all components.
Position Furnace: Level unit and ensure proper clearance to combustibles.
Ductwork Connection: Attach supply and return ducts with proper sealing.
Gas Line Connection: Install gas line with sediment trap and shutoff valve.
Electrical Wiring: Connect line voltage and thermostat wiring.
Venting Installation: Install vent pipes according to local codes.
Condensate Drain: Connect condensate line for high-efficiency models.

WARNING! Installation must comply with local codes and manufacturer specifications. Professional installation recommended.

Electrical Connections

Proper electrical wiring and connection procedures.

Disconnect power at main electrical panel before beginning work.
Verify voltage: 120V AC, 60Hz with proper circuit protection.
Connect line voltage wiring to furnace junction box.
Install 24V thermostat wiring following wiring diagram.
Connect ground wire to furnace chassis.
Verify proper polarity and secure all connections.
Install access panel before restoring power.

CAUTION! Incorrect wiring can cause equipment damage and safety hazards.

Gas Line Connections

Gas piping installation and leak testing procedures.

Use black iron pipe or approved flexible connector.
Install sediment trap ahead of gas valve.
Use pipe compound rated for natural/LP gas on threaded connections.
Install manual shutoff valve within 6 feet of furnace.
Pressure test gas line at 14" WC for 10 minutes (no drop).
Check all connections with soap solution for leaks.
Connect flexible gas connector if required.
Verify proper gas pressure at manifold.

DANGER! Gas leaks can cause explosion or fire. Test thoroughly.

Venting Requirements

Vent system specifications and installation guidelines.

Vent Type	Requirements
Category I	Natural draft; vertical vent with proper clearance
Category IV	Direct vent or concentric; PVC pipe approved
Horizontal Vent	1/4" per foot slope toward furnace
Vertical Vent	Minimum height per local codes
Clearances	Maintain required clearance to combustibles
Termination	Proper location away from windows and air intakes

Startup and Operation

Initial startup procedure and normal operation sequence.

Verify all installation steps are complete and proper.
Restore electrical power to furnace.
Open gas shutoff valve slowly.
Set thermostat to heating mode above room temperature.
Observe ignition sequence: inducer motor, pressure switch, igniter, gas valve.
Verify flame establishment and proper burner operation.
Check temperature rise against specifications.
Verify proper blower operation and air delivery.
Cycle system multiple times to ensure reliable operation.

Control System Overview

Integrated furnace control board and diagnostic system.

Control Board: Microprocessor-based with LED diagnostic codes.

Safety Controls: Limit switches, pressure switches, flame sensor, rollout switches.

Diagnostic Codes: Flash codes for troubleshooting (refer to specific model manual).

Blower Control: Variable speed operation with timed delays.

Ignition Control: Monitors flame sense and provides safety shutdown.

Maintenance Procedures

Routine maintenance schedule and procedures.

Monthly: Check air filter; replace if dirty.
Annual: Professional inspection and cleaning.
Clean burners and heat exchanger surfaces.
Inspect and clean flame sensor.
Check vent system for obstructions.
Verify gas pressure and combustion analysis.
Lubricate inducer motor if required (non-sealed bearings).
Check electrical connections for tightness.
Test safety controls and operation sequence.

Important: Regular maintenance ensures efficiency and prevents breakdowns.

Troubleshooting Guide

Common problems and solutions for Nordyne gas furnaces.

Symptom	Possible Cause	Corrective Action
No heat	Power loss, thermostat, gas valve	Check power, thermostat setting, gas supply
Furnace won't start	Door switch, limit switch, pressure switch	Verify door closure, check switches for continuity
Short cycling	Dirty filter, high limit, airflow	Replace filter, check airflow, verify limit operation
Blower won't run	Motor, capacitor, control board	Check voltage to motor, test capacitor, verify control signal
No ignition	Igniter, gas valve, pressure switch	Test igniter for continuity, verify gas pressure, check pressure switch
Flame rollout	Blocked heat exchanger, venting	Inspect heat exchanger, check vent for obstructions
Error codes	Various faults	Refer to diagnostic chart for specific code

Parts List and Diagrams

Common replacement parts and exploded view diagrams.

Heat Exchanger: Model-specific replacement
Igniter: Silicon nitride hot surface igniter
Gas Valve: Combination gas control valve
Blower Motor: ECM or PSC motor assembly
Control Board: Integrated furnace controller
Flame Sensor: Rod-type flame detection
Pressure Switch: Diaphragm-type safety switch
Limit Switches: High temperature safety controls
Inducer Motor:Combustion blower assembly