The Lennox Pulse Furnace A-Series is a high-efficiency gas furnace featuring pulse combustion technology, electronic ignition, variable-speed blower motor, and advanced diagnostic systems. Designed for residential heating applications with AFUE ratings up to 97%, these furnaces include safety controls, pressure switches, condensate drainage, and compatibility with various thermostat systems. Below are key sections for safety, features, installation, operation, maintenance, and troubleshooting.
Key components: Pulse combustion system, heat exchanger, induced draft blower, gas valve, pressure switches, control board, blower motor, flame sensor, and diagnostic LEDs.
| Feature | Description |
|---|---|
| Pulse Combustion | High-efficiency combustion technology with spark ignition |
| Variable Speed Blower | ECM motor for precise airflow control and quiet operation |
| Diagnostic System | LED status lights for error code identification |
| Pressure Switches | Safety verification of proper venting operation |
| Gas Valve | Electronic modulation for precise fuel control |
| Heat Exchanger | Stainless steel construction for durability |
| Condensate Drain | Removes combustion byproduct water |
| Control Board | Microprocessor-based operation and timing |
| Flame Sensor | Verifies burner ignition |
| Thermostat Compatibility | Works with standard 24VAC thermostats |
Professional installation required. Verify local codes and obtain permits.
WARNING! Gas appliances can be hazardous; installation must comply with all local codes and manufacturer specifications. Carbon monoxide poisoning risk if improperly installed.
Initial startup must be performed by qualified technician.
CAUTION! Never bypass safety controls. Ensure proper combustion air and venting before operation.
Operation controlled by integrated control board responding to thermostat signals.
Normal Operation Sequence: Thermostat call for heat → Inducer motor starts → Pressure switch verification → Spark ignition → Gas valve opens → Flame establishment → Blower starts after heat exchanger warm-up.
Control Board Features: LED status indicators, diagnostic codes, timing functions, blower control, safety lockout.
Thermostat Settings: Heat mode, fan auto/on, temperature setpoint. Compatible with single-stage and programmable thermostats.
Direct vent system required using approved PVC or CPVC pipe.
Tip: Regularly inspect vent terminations for blockages from snow, ice, or debris.
Annual maintenance by qualified technician recommended.
WARNING! Always disconnect power and gas supply before performing maintenance.
Multiple safety systems protect against hazardous conditions.
| Safety Feature | Function |
|---|---|
| Pressure Switches | Verify proper inducer operation and venting |
| Flame Rollout Switches | Detect improper burner flames |
| High Limit Switches | Prevent overheating of heat exchanger |
| Flame Sensor | Confirms burner ignition within trial period |
| Ignition Control | Limits ignition attempts before lockout |
| Gas Valve | Automatic shutoff if flame not detected |
Regular maintenance ensures optimal performance and longevity.
Monthly: Check and replace air filter as needed. Visual inspection of vent termination.
Annual: Professional cleaning and inspection including heat exchanger, burners, blower, drain system, and safety controls.
CAUTION! Never operate furnace without proper air filter. Keep area around furnace clean and free of combustible materials.
UL listed and ANSI certified for safety. Complies with ANSI Z21.47 standards for gas-fired central furnaces. CSA International certified for Canadian installations. Manufactured to meet DOE energy efficiency standards. For technical support and warranty service, contact Lennox Industries at 1-800-9-LENNOX or visit www.lennox.com.
| Symptom | Possible Cause | Corrective Action |
|---|---|---|
| Furnace won't start | Power, thermostat, door switch | Check circuit breaker, thermostat settings, ensure door properly closed |
| No heat | Gas supply, ignition, safety lockout | Verify gas valve on, check for spark, reset power to clear lockout |
| Short cycling | Dirty filter, limit switch, airflow | Replace filter, check blower operation, verify proper airflow |
| Blower won't stop | Thermostat fan setting, control board | Check thermostat fan setting (auto/on), inspect control board |
| Error codes flashing | Various system faults | Refer to diagnostic chart in manual for specific code meaning |
| Condensate leakage | Clogged drain, trap issues | Clear drain line, check condensate trap, ensure proper slope |
Reset Procedure: Turn thermostat off, disconnect power for 30 seconds, restore power, turn thermostat on.
Service: 1-800-9-LENNOX; www.lennox.com