Lennox 74N47 HSI Ignitor

The Lennox 74N47 HSI Ignitor is a high-performance, OEM-grade hot surface ignitor specifically engineered for precision ignition in Lennox gas furnaces and condensing water boilers, including GWB9 series models. As a veteran technician knows, maintaining reliable combustion starts with a fast-acting 120V element. This silicon carbide ignitor provides the necessary thermal mass to reach ignition temperatures rapidly, ensuring the gas valve opens to a consistent heat source. Designed to replace aging or cracked elements that trigger Lennox error code E207, this kit features the standard two-pin Molex connector for a direct, plug-and-play fit without the need for harness splicing or bracket retrofitting.

When performing a furnace ignitor replacement, verify that your control board is delivering the correct 120V AC signal. This genuine 74N47 ignitor is built for durability in high-cycle environments but remains sensitive to surface contaminants. To avoid premature failure, handle the ceramic base only and keep the element clear of skin oils and drywall dust. This OEM component ensures your system stays within the manufacturer-rated resistance range of 39 to 70 ohms, preserving the integrity of the integrated furnace control board and preventing nuisance lockouts during peak heating demands.

• Direct OEM Compatibility: Built specifically for Lennox and Allied Air platforms, ensuring perfect alignment with the burner flame pattern.
• Broad Application: Primary ignition source for GWB9-050IH, GWB9-075IH, and GWB9-100IH high-efficiency boilers.
• High Durability: Engineered to withstand the thermal stress of modern high-efficiency furnace cycles.
• Seamless Integration: Factory-terminated harness with the correct Molex plug prevents high-resistance connections often found in universal kits.

• What is the correct resistance for the 74N47? Bench testing should typically show between 39 and 70 ohms at room temperature. An "OL" or high-kiloohm reading indicates a micro-crack requiring replacement.
• Does this replace older silicon nitride versions? This is the specified OEM replacement for the 74N47/43800013 series. Always match the voltage (120V) to your specific furnace control output.
• Will this fix a furnace that clicks but won't light? If the inducer is running and you hear the gas valve click but see no orange glow from the furnace igniter, this component likely has an open circuit.

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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.