Introduction
This manual provides essential information for the safe and proper installation, operation, and maintenance of the Lennox 97L4801 OEM Replacement Furnace Control Board. This control board is designed to manage the ignition sequence, flame sensing, and various timing functions for gas-fired non-integrated forced-air furnaces, boilers, and cooking appliances. Please read all instructions carefully before proceeding with installation or operation.
Safety Information
WARNING: Improper installation, adjustment, alteration, service, or maintenance can cause property damage, personal injury, or loss of life. Installation and service must be performed by a qualified installer, service agency, or the gas supplier.
- Always disconnect electrical power to the furnace before servicing to prevent electrical shock.
- Ensure all wiring connections comply with local and national electrical codes.
- Verify proper grounding of the furnace and control board.
- Do not operate the furnace if any part has been submerged in water. Immediately call a qualified service technician to inspect the furnace and replace any part of the control system and gas control that has been submerged in water.
- Handle the control board with care to avoid damage from static electricity.
Setup and Installation
The Lennox 97L4801 control board is an OEM replacement part. While designed for compatibility, variations may exist between older and newer board designs. Professional installation is highly recommended.
Installation Steps:
- Disconnect Power: Turn off all electrical power to the furnace at the main service panel.
- Access Control Board: Locate and open the furnace access panel to expose the existing control board.
- Document Wiring: Before disconnecting any wires, take clear photographs or make detailed diagrams of all existing wiring connections to the old control board. Pay close attention to the thermostat wires and main power connections.
- Disconnect Wires: Carefully disconnect all wires from the old control board. Label each wire as it is removed to ensure correct re-connection.
- Remove Old Board: Unmount the old control board from its position.
- Install New Board: Mount the new Lennox 97L4801 control board in the same location. Ensure it is securely fastened.
- Connect Wiring: Reconnect all wires to the new control board according to your documentation. Note that the new board may have different connector configurations (e.g., 4-pin and 12-pin connectors instead of 6-pin and 9-pin) and the thermostat wire order might differ. Use any provided adapter wires if necessary. Ensure all connections are firm and correct.
- Verify Connections: Double-check all wiring against your documentation and the new board's labels.
- Restore Power: Close the furnace access panel and restore electrical power to the furnace.
- Test Operation: Initiate a heating cycle to verify proper furnace operation. Observe the ignition sequence and overall performance.
Image: Comparison of an older Lennox furnace control board (left) and the new 97L4801 replacement board (right), highlighting potential differences in layout and connector types. The new board may require adapting existing wiring due to changes in pin configurations and thermostat wire placement.
Operating Instructions
The Lennox 97L4801 control board operates automatically once installed and power is supplied. It manages the furnace's heating and cooling cycles based on thermostat demands.
- Ensure your thermostat is set to the desired mode (Heat/Cool) and temperature.
- The control board will initiate the appropriate sequence:
- Heating Cycle: Inducer motor activation, hot surface igniter warm-up, gas valve opening, flame sensing, and blower motor activation after a heat delay.
- Cooling Cycle: Blower motor activation upon demand from the thermostat.
- The board incorporates various safety features, including flame failure response and limits for heat and cool delays.
Maintenance
The control board itself requires no routine maintenance. However, regular maintenance of the entire furnace system is crucial for its longevity and efficient operation.
- Have your furnace inspected annually by a qualified HVAC technician.
- Regularly replace or clean your furnace air filter as recommended by your furnace manufacturer.
- Keep the area around the furnace clear of obstructions and combustible materials.
Troubleshooting
The 97L4801 control board features diagnostic indicators to assist in identifying operational issues. Refer to your furnace's specific diagnostic chart for detailed interpretations.
Common Diagnostic Codes (Refer to board labels for specifics):
- Slow Flash: Indicates a specific fault condition, often related to a safety limit being open or a watch guard burner issue.
- Fast Flash: May indicate a different fault, such as a reverse polarity condition or a specific heat demand issue.
- Alternate Flash: Suggests a more complex issue, potentially involving simultaneous safety limits or other system errors.
General Troubleshooting Steps:
- No Heat/No Cool: Check thermostat settings, ensure power is supplied to the furnace, and verify circuit breakers.
- Furnace Not Firing: Observe the diagnostic light on the control board. Check for proper gas supply and ensure the igniter is functioning.
- Continuous Cycling: This could indicate a faulty limit switch, flame sensor, or an issue with the thermostat.
- Blower Not Operating: Check for proper wiring to the blower motor and ensure the thermostat is calling for fan operation.
If troubleshooting steps do not resolve the issue, contact a qualified HVAC technician for further diagnosis and repair.
Specifications
| Feature | Detail |
|---|---|
| Model Number | 97L4801 |
| Brand | Lennox |
| Product Dimensions | 6 x 6 x 6 inches |
| Item Weight | 1.5 pounds |
| Ignition Type | Hot Surface Ignition |
| Fuel Type Compatibility | Natural, Manufactured, Mixed, Liquefied Petroleum, and Liquid Propane Gas |
| Flame Sense Type | Remote, Integrated |
| Ignition Sequence | 4-Trial Prepurge Time 15 Second |
| Flame Failure Response Time | 2 Second |
| Input Voltage | 25 Volt AC at 50/60 Hertz |
| Temperature Rating | -40 to 175 Deg F |
| Humidity Range | 5 to 93 Percent Relative Humidity |
| Auto-Reset Time | 60 Minute |
Warranty Information
This Lennox 97L4801 OEM Replacement Furnace Control Board is covered by the manufacturer's standard warranty. Please retain your proof of purchase for warranty claims. For specific warranty terms and conditions, refer to the documentation provided with your original furnace or contact Lennox customer support.
Customer Support
For technical assistance, installation questions, or troubleshooting guidance beyond the scope of this manual, please contact a qualified HVAC professional or Lennox customer service. Always provide your product model number (97L4801) when seeking support.
