Lennox 79L59 Flame Sensor Wire

The Lennox 79L59 Flame Sensor Wire is a critical OEM replacement component designed to maintain the integrity of the flame rectification circuit in gas-fired heating systems. This high-temperature lead provides a direct, low-resistance path between the flame sensor rod and the integrated furnace control (IFC). As a veteran technician knows, flame sensor signal loss often stems from brittle or corroded wiring rather than just the sensor itself. The Lennox 79L59 is engineered specifically to withstand the intense thermal cycling and high-ambient cabinet temperatures common in modern high-efficiency units. It is identical to part number 79L5901, ensuring a seamless drop-in fit for older Lennox inventory. Utilizing this genuine HVAC replacement part prevents nuisance lockouts caused by microamp signal degradation, which standard generic wire cannot reliably mitigate. Whether servicing a residential Lennox furnace or a commercial T-Class unit, this wire is essential for preventing furnace ignition failure and ensuring accurate flame presence detection during the combustion cycle.

• OEM Compatibility: Fully interchangeable with Lennox 79L5901, offering a 1:1 match for factory specifications and connector types.
• High-Temperature Insulation: Specifically rated for combustion environments, preventing insulation breakdown and short-to-ground faults.
• Optimal Signal Integrity: Designed to carry low-voltage microamp signals without impedance issues that lead to intermittent furnace flame sensor errors.
• Direct Fit: Features factory-crimped terminals for a secure, vibration-resistant connection to both the control board and the sensor.

Is the 79L59 compatible with all Lennox furnace models?
While the Lennox 79L59 Flame Sensor Wire is widely used across Lennox G-series and elite series units, always verify your specific model number. It is most commonly found in models ranging from TUA045SNAF-1 to TUA300SNSF-1.

Can I use a standard 18AWG wire instead of this OEM lead?
Standard wire often lacks the high-temperature jacket required for proximity to the burner assembly. Using the Lennox OEM 79L59 ensures the insulation will not melt or crack, which would otherwise ground out the signal and cause a system lockout.

When should this wire be replaced during a service call?
Inspect this lead if you are measuring low microamps at the board despite a clean sensor. If the casing is brittle or the connectors show signs of silvering or oxidation, replacing the flame sensor wire is a proactive step to ensure long-term system reliability.

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.