Lennox 73K38 Ignitor

When you're facing a "no ignition" call on a Lennox furnace, the Lennox 73K38 Ignitor is the precision-engineered OEM replacement part you need to restore system reliability. This Direct Spark Ignition (DSI) component is built for high-performance gas-fired appliances, featuring a 2.65-inch electrode length and "L" style mounting bracket to ensure exact alignment with the burner assembly. Engineered with high-temperature resistant materials, the 73K38 delivers a consistent high-voltage arc, eliminating the common failure points of universal "will-fit" ignitors that often lead to delayed ignition or nuisance lockouts. As a Genuine Lennox HVAC part, it integrates seamlessly with the existing SureLight ignition control board, maintaining the safe and efficient startup sequence required for residential and commercial heating units. For technicians, using the 73K38 ensures the repair meets original manufacturer specifications, providing a rugged solution for furnace ignition repair and long-term HVAC system performance.

Key Benefits for the HVAC Contractor:

• Exact OEM Specifications: Matches the thermal and electrical profiles required for compatible Lennox, Armstrong, and Ducane furnaces.
• Industrial Durability: Specifically designed to withstand the intense combustion environment without premature electrode degradation.
• Simplified Installation: Features the original plug-and-play wiring harness and bracket geometry for fast ignition replacement.
• System Safety: Prevents gas buildup by providing instantaneous ignition, ensuring a reliable "prove" signal to the flame sensor.

Common Questions:

How do I know if my Lennox ignitor is bad?
If the furnace inducer motor runs but you don't see a spark or hear the distinct clicking of the DSI, check for 24V or 120V (depending on your specific control board) at the ignitor terminal. Visible cracks or a "dead patch" on the electrode also indicate it's time for a furnace ignitor replacement.

Will a universal ignitor work for the 73K38?
While some universal kits exist, Lennox DSI systems are sensitive to electrode length and positioning. The 73K38 (73K3801) ensures the spark occurs exactly in the gas-air mixture path, preventing the delayed ignition issues often caused by shorter universal alternatives.

What is the difference between HSI and DSI ignitors?
The 73K38 is a Direct Spark Ignitor (DSI), which uses high-voltage electricity to create a spark, similar to a spark plug. This is different from Hot Surface Ignitors (HSI) which glow orange to ignite the gas. Ensure your system is rated for DSI before installation.

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.