Lennox 98M87 Flame Sensor

The Lennox 98M87 Flame Sensor (Catalog Number 98M87) is a critical OEM diagnostic component for Lennox furnace control systems. Built specifically to handle high-temperature combustion environments, this sensor generates the microamp signal necessary for the integrated furnace control (IFC) to verify flame rectificaton. Identifying a Lennox 44745-001 or 98M8701 in the field often necessitates this direct replacement to resolve furnace ignition failure or intermittent furnace lockout codes. This sensor features a high-grade Kanthal metal probe and a glazed ceramic insulator to prevent electrical leakage to ground, ensuring precise flame current readings. When troubleshooting a Lennox flame sensor replacement, technicians should note that this unit is a drop-in match for legacy R44745-001 models, maintaining the exact offset and insertion depth required for the burner assembly's pilot or main burner flame path. Using a genuine Lennox 98M87 ensures the millivolt signal remains within the manufacturer’s specified range for reliable heating cycles.

Key Benefits for Technicians

• Direct OEM Compatibility: Replaces Lennox 98M8701 and R44745-001 without modifications to the mounting bracket or wiring harness.
• Precision Flame Rectification: Engineered to provide consistent microamp output to the control board, reducing nuisance trips.
• High-Heat Resilience: The 98M87 flame sensor utilizes specialized alloys to resist carbon buildup and oxidation in high-efficiency Lennox furnaces.
• Service Efficiency: Features a standard 1/4-inch male spade terminal for rapid connection during emergency service calls.

Common Questions

How do I test the Lennox 98M87 Flame Sensor?
Set your multimeter to the DC microamp (µA) scale. Connect the meter in series between the flame sensor wire and the control board terminal. A healthy Lennox 98M87 typically produces a signal between 1.5 and 5.0 microamps depending on the specific furnace model.

Can I clean the 98M8701 sensor instead of replacing it?
While cleaning with a light abrasive can temporarily restore signal, microscopic pitting on the 44745-001 probe surface leads to rapid carbon re-accumulation. For long-term reliability and to prevent repeat service calls, a full Lennox flame sensor replacement is the professional standard.

What causes a Lennox 98M87 to fail?
Common failure points include cracked ceramic insulators causing a short to ground or heavy oxidation on the probe which acts as an insulator, preventing the furnace flame sensor from detecting the burner flame.

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.