Lennox 49M85 Ignitor

For service technicians maintaining Lennox gas furnaces, the Lennox 49M85 Spark Ignitor (also identified as 49M8501) is an essential OEM replacement component designed to ensure consistent combustion. This spark electrode ignitor is specifically engineered for Lennox KGA and ZGA series units, providing the precision arc necessary for reliable burner ignition. Constructed by Precision Speed Equipment (PSE-L60), the assembly features a glazzed L-5 steatite or alumina insulator and a copper-plated ground plate, offering superior heat resistance in high-temperature combustion chambers. As a genuine Lennox furnace part, it integrates seamlessly into factory wiring harnesses, eliminating the need for field modifications. Replacing a pitted or oxidized Lennox 49M85 ignitor electrode prevents common ignition failures and "No Heat" lockouts, maintaining the original equipment performance standards expected in light commercial and residential applications. Professional installation is recommended to ensure proper gap alignment and spark intensity across the burner interface.

Key Benefits for Technicians:

• Exact OEM Compatibility: Proper fitment for Lennox, Armstrong, and Ducane gas furnaces using the 49M8501 specification.
• High-Grade Insulation: Utilizes glazed alumina or L-5 steatite to prevent voltage leakage and ensure a focused spark.
• Durable Construction: The copper-plated ground plate and 4-inch length are designed to withstand repeated thermal cycling without premature degradation.
• Reliable Cold Starts: Ensures a dependable ignition arc, reducing misfires and system lockout errors during peak demand.

Common Troubleshooting Questions:

How do I know if my Lennox 49M85 needs replacement?
If the furnace control board indicates a dedicated "Ignition Failure" code or if you observe visible pitting, cracks, or heavy carbon buildup on the electrode tip, the component should be replaced. A lack of a visible spark during the ignition sequence often points to a failed electrode or a cracked ceramic insulator.

Is the 49M85 compatible with 80V or 120V systems?
The Lennox 49M85 is a spark electrode, not a hot surface ignitor (HSI). It is designed to work with integrated furnace controls that utilize high-voltage spark ignition. Always verify that your specific model number calls for a spark electrode rather than a nitride or carbide HSI.

Can I clean the electrode instead of replacing it?
While light oxidation can sometimes be removed with fine steel wool, a technician should replace the part if the metal is pitted or the ceramic insulator is compromised. Any hairline cracks in the insulator can cause the spark to ground out before reaching the burner, leading to intermittent failures.

Disclaimer: While we strive for 100% accuracy, product data and specifications are subject to change. Please contact our team to confirm compatibility or technical details before purchasing.