The Lennox Pulse Furnace is a high-efficiency gas furnace featuring pulse combustion technology, electronic ignition, stainless steel heat exchangers, and advanced control systems. This manual provides comprehensive information on parts identification, replacement procedures, safety guidelines, and maintenance schedules for proper furnace operation and service.
Before servicing any furnace components, ensure proper safety protocols are followed.
| Safety Precaution | Description |
|---|---|
| Gas Supply Shutoff | Always turn off gas supply before servicing |
| Electrical Disconnect | Disconnect power at service panel |
| Carbon Monoxide Detection | Ensure proper ventilation and CO detectors installed |
| Heat Exchanger Inspection | Check for cracks or damage before operation |
| Combustion Air Requirements | Verify adequate combustion air supply |
| Vent System Integrity | Inspect vent pipes for obstructions or damage |
| Personal Protective Equipment | Wear safety glasses and gloves during service |
Key components of the Lennox Pulse Furnace system.
WARNING! Only qualified technicians should service gas furnace components. Improper installation or repair can create hazardous conditions.
Electronic control system parts and functions.
| Component | Part Number | Function |
|---|---|---|
| Main Control Board | 10F83 | Primary furnace operation control |
| Ignition Control | 15F96 | Pulse combustion ignition sequence |
| Pressure Switch | 10D51 | Verifies proper vent operation |
| Flame Sensor | 20F04 | Detects flame presence |
| Limit Switch | 10L51 | High temperature safety cutoff |
| Rollout Switch | 10L50 | Flame rollout safety device |
| Thermostat Terminal | 69L46 | External control connection |
Stainless steel heat exchanger components and specifications.
Pulse combustion components and gas train parts.
CAUTION! Combustion system service requires specialized training and equipment.
Air handling and ventilation system parts.
| Component | Part Number | Specifications |
|---|---|---|
| Blower Motor | 13W22 | Multi-speed direct drive, 1/3 HP |
| Blower Wheel | 20H62 | Forward-curved aluminum wheel |
| Motor Capacitor | 24F93 | 7.5 MFD, 370 VAC run capacitor |
| Blower Housing | 30H64 | Galvanized steel construction |
| Vent Blower | 13W35 | Combustion exhaust blower assembly |
| Draft Inducer | 13W40 | Vent system pressure maintenance |
Electrical system parts and wiring components.
Step-by-step component replacement guidelines.
WARNING! Always verify proper operation and check for gas leaks after service.
Recommended maintenance intervals and procedures.
| Maintenance Task | Frequency | Procedure |
|---|---|---|
| Air Filter Replacement | Monthly | Replace or clean air filter |
| Heat Exchanger Inspection | Annually | Visual inspection for cracks or damage |
| Blower Cleaning | Annually | Clean blower wheel and housing |
| Vent System Inspection | Annually | Check for obstructions or damage |
| Gas Valve Operation | Annually | Verify proper gas pressure and operation |
| Electrical Connections | Annually | Check and tighten all electrical connections |
Common issues and diagnostic procedures.
| Symptom | Possible Cause | Corrective Action |
|---|---|---|
| Furnace won't start | Power supply, thermostat, door switch | Check circuit breaker, thermostat settings, door switch engagement |
| No heat | Gas supply, ignition failure, pressure switch | Verify gas valve open, check ignition system, test pressure switch |
| Short cycling | Dirty filter, blocked vent, limit switch | Replace air filter, clear vent obstructions, check limit switch |
| Blower not running | Motor, capacitor, control board | Test motor windings, check capacitor, verify control signals |
| Unusual noises | Loose components, bearing wear | Tighten mounting hardware, inspect blower bearings |
| Error codes flashing | System faults | Refer to diagnostic code chart in service manual |
Service Support: 1-800-9-LENNOX; www.lennox.com