Lennox 20J90 Ignitor

As a seasoned technician, you know that a reliable ignition sequence is the backbone of any call-back-free furnace repair. The Lennox 20J90 Electrode/Spark Ignitor is a genuine OEM replacement designed specifically for high-performance Lennox unit heaters and furnaces. This L-style spark electrode features a precision-engineered 2.61-inch electrode length and a total ignitor length of 2-7/8 inches, ensuring the arc reaches the gas stream at the exact coordinates required for a clean, immediate light-off. Operating within the SureLight ignition system, this component eliminates the common frustration of delayed ignition or "Watchguard" lockouts caused by weak or intermittent sparking.

When you are out in the field dealing with LF24 series unit heaters or UHPA models, using an exact-match Lennox 20J9001 replacement is non-negotiable for maintaining the manufacturer's specified combustion timing. The bracketed 2-inch mounting base provides a secure, vibration-resistant fit that prevents the electrode gap from shifting during high-static blower cycles. Whether you are performing a seasonal tune-up or a critical no-heat emergency repair, this durable metal electrode is built to withstand the thermal stress of repeated ignition cycles without premature carbon fouling or ceramic cracking.

• Exact OEM Compatibility: Directly replaces Lennox, Armstrong, and Ducane part numbers 20J90, 20J9001, and 20515901 for a drop-in fit.
• Reliable "L" Style Geometry: Optimized 1-3/4" distance to the "L" bend and 1-1/8" distance to the tip for precise spark gap placement.
• System Integrity: Engineered to work seamlessly with integrated furnace control boards to prevent nuisance flame sense errors.
• Rugged Construction: High-grade ceramic insulator and durable metal tip designed for high-temperature furnace environments.

• What causes a "4+7" flash code on the control board? In Lennox systems, this typically indicates an ignitor circuit fault. Check the 20J90 for cracked ceramic or a grounded tip before replacing the board.
• Can this be used in LF24-50 through LF24-300 models? Yes, this is the standard spark electrode for the popular LF24 series unit heaters, ensuring consistent performance across various BTU ratings.
• Why is my furnace clicking but not lighting? If you hear the spark but see no flame, the electrode may be fouled or misaligned. Replacing it with a fresh 20J90 spark ignitor restores the high-energy arc required for gas ignition.

This item is not eligible for free shipping.

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.