Lennox 13H25 Assembly

The Lennox 13H25 Electrode and Sensor Assembly is the critical OEM ignition and flame detection component for high-efficiency Lennox gas furnaces. Functioning as a dual-purpose unit, this assembly integrates a high-voltage spark electrode and a flame rectification sensor onto a single pre-formed mounting bracket. It is the direct factory replacement for the legacy Lennox 13H2501 part number. Designed to withstand the extreme thermal cycles of the burner box, the 13H25 ensures precise furnace ignition and continuous flame monitoring, preventing hazardous unburned gas accumulation. For technicians performing HVAC troubleshooting, the 13H25 is a primary solution for addressing frequent furnace ignition failure or intermittent "no heat" calls. This genuine Lennox furnace replacement part maintains the exact tolerances required for safe operation and optimal combustion efficiency. When diagnosing a dirty flame sensor or cracked ceramic insulator, replacing the entire 13H25 electrode assembly is the standard industry practice to ensure long-term system reliability.

• Dual-Function Integration: Combines the ignition source and flame monitoring into one unit for streamlined installation and maintenance.
• OEM Precision: Guaranteed Lennox 13H2501 compatibility, ensuring the sensor rod and electrode are positioned at the precise factory-specified depth.
• Thermal Durability: Engineered with high-grade ceramic insulation and heat-resistant alloys to prevent cracking and electrical shunts in high-heat environments.
• Plug-and-Play Setup: Features pre-formed terminals and a 45-degree sensor angle for quick connection to existing wiring harnesses.

How do I know if my Lennox 13H25 assembly is failing?
Common symptoms include the furnace attempting to ignite (sparking) but shutting down after a few seconds, or a diagnostic LED code on the control board indicating a "Low Flame" or "Flame Out of Sequence" error (often Code E241).

Can I just clean the 13H25 sensor rod instead of replacing it?
While cleaning a carbon-coated rod with a fine abrasive may provide a temporary fix, widespread oxidation or a hairline crack in the ceramic insulator requires a full Lennox electrode replacement to restore safe, consistent furnace operation.

Is the 13H25 the correct part for my Lennox model?
The 13H25 is a common component in Lennox G-series and EL-series high-efficiency furnaces. However, always verify compatibility using your specific unit model and serial number before ordering.

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.