Lennox Elite Series Furnace Service Manual

The Lennox Elite Series Furnace is a high-efficiency gas furnace designed for residential heating applications. This service manual covers installation, operation, maintenance, and troubleshooting procedures for certified HVAC technicians. The Elite Series features advanced diagnostics, variable-speed blower technology, and compatibility with Lennox iComfort thermostats for optimal performance and energy efficiency.

1. Safety Precautions 2. Technical Specifications 3. Installation Guidelines 4. Electrical Connections 5. Gas Supply Requirements 6. Venting System 7. Startup Procedure 8. Operating Instructions 9. Maintenance Schedule 10. Diagnostic Codes 11. Troubleshooting Guide

Safety Precautions

Critical safety information for proper furnace installation and service.

Hazard	Precaution
Gas Leaks	Check all connections with leak detection solution before startup
Electrical Shock	Disconnect power before servicing electrical components
Carbon Monoxide	Ensure proper venting and combustion air supply
High Temperatures	Allow furnace to cool before handling heat exchanger
Moving Parts	Keep hands clear of blower wheel during operation

Technical Specifications

Models: EL195UH, EL296UH, EL297UH Series
Input Capacity: 40,000 to 120,000 BTU/H
AFUE Rating: Up to 98.7%
Voltage: 120V AC, 60Hz
Gas Type: Natural Gas or LP (with conversion kit)
Gas Pressure: Natural Gas: 3.5" WC, LP: 10" WC
Blower Type: Variable Speed ECM Motor
Control System: Integrated Furnace Controller with LED diagnostics

Installation Guidelines

Proper installation ensures optimal performance and safety.

Location: Install in clean, dry area with adequate clearance for service access
Combustion Air: Provide sufficient combustion and ventilation air per local codes
Leveling: Ensure furnace is level for proper condensate drainage
Ductwork: Size ductwork according to Manual J calculation
Clearances: Maintain minimum clearances: 1" sides, 6" front, 24" top

WARNING! Installation must comply with all local codes and regulations. Only qualified technicians should install this equipment.

Electrical Connections

Wiring requirements and connection procedures.

Disconnect power before making electrical connections
Connect 120V power supply to furnace junction box
Install dedicated 15-amp circuit breaker
Connect thermostat wires to control board terminals
Verify proper grounding of all electrical components

CAUTION! Reverse polarity will damage control board. Verify hot and neutral connections.

Gas Supply Requirements

Gas line sizing and pressure verification.

Pipe Size	Maximum Length	BTU/H Capacity
1/2"	30 feet	Up to 80,000 BTU/H
3/4"	50 feet	Up to 120,000 BTU/H
1"	100 feet	Up to 200,000 BTU/H

Verify manifold pressure: Natural Gas 3.5" WC ± 0.3", LP Gas 10" WC ± 0.5"

Venting System

PVC vent pipe installation guidelines.

Use only schedule 40 PVC or CPVC pipe
Maintain minimum 1/4" per foot slope toward furnace
Maximum vent length: 100 feet equivalent (including elbows)
Install condensate drain trap per manufacturer specifications
Terminate vents according to local code requirements

IMPORTANT: Do not reduce vent pipe size. Maintain proper clearances from windows and doors.

Startup Procedure

Step-by-step furnace commissioning process.

Verify all connections are secure and proper
Check gas pressure and adjust if necessary
Set thermostat to heating mode and raise temperature
Observe ignition sequence and flame characteristics
Measure temperature rise and adjust blower speed
Verify proper condensate drainage
Complete combustion analysis and record readings

Operating Instructions

Normal operation and user controls.

Thermostat Settings: Compatible with Lennox iComfort thermostats for optimal efficiency

Blower Operation: Variable speed motor adjusts airflow based on heating demand

Ignition Sequence: Hot surface igniter with flame sensor safety

LED Status Light: Blinks normal operation code (1 flash every 3 seconds)

Maintenance Schedule

Recommended maintenance intervals for optimal performance.

Maintenance Task	Frequency
Replace air filter	Every 1-3 months
Inspect heat exchanger	Annually
Clean blower assembly	Annually
Check vent system	Annually
Verify gas pressure	Annually
Lubricate induced draft motor	As needed

Diagnostic Codes

LED flash codes for troubleshooting.

Flash Code	Description	Action
1 Flash	Normal operation	No action required
2 Flashes	Pressure switch error	Check venting and inducer
3 Flashes	Ignition failure	Check gas supply and igniter
4 Flashes	Flame sense error	Clean flame sensor
5 Flashes	High limit switch	Check airflow and filter
6 Flashes	Rollout switch	Check heat exchanger

Troubleshooting Guide

Symptom	Possible Cause	Corrective Action
Furnace won't start	Power loss, thermostat issue	Check circuit breaker, thermostat settings
No heat	Gas valve closed, igniter failure	Verify gas supply, check igniter continuity
Short cycling	Dirty filter, high limit trip	Replace filter, check airflow
Blower won't run	Motor failure, capacitor issue	Test motor windings, check capacitor
Unusual noises	Loose components, bearing wear	Tighten mounting hardware, inspect bearings

Technical Support: 1-800-9-LENNOX

Website: www.lennox.com