Lochinvar & A.O. Smith 100074673 Flame Rod

The Lochinvar and A.O. Smith 100074673 Flame Rod is a critical safety component designed for precise flame rectification sensing in high-efficiency commercial boilers and water heaters. This OEM replacement part, formerly identified as Lochinvar PLT3022, monitors the burner's pilot or main flame by generating a microamp signal to the ignition control module. Engineered for compatibility with Lochinvar Knight, Armor, and Shield series models, this flame sensor ensures stable combustion and prevents nuisance lockouts caused by carbon buildup or high-temperature oxidation. As a HVAC replacement part, it utilizes high-grade alumina ceramic insulation and a durable metal electrode to withstand the intense thermal environment of the combustion chamber. When diagnosing boiler ignition failure or intermittent E02 flame failure codes, inspecting this sensor for cracks or contamination is a standard troubleshooting protocol for licensed technicians maintaining Lochinvar heating systems.

• Precise Rectification: Delivers accurate microamp feedback to the control board to maintain consistent burner operation.
• OEM Compatibility: Exact fit for A.O. Smith and Lochinvar equipment, ensuring seamless integration with existing wiring harnesses.
• Thermal Resistance: High-quality ceramic housing prevents electrical grounding and withstands extreme operating temperatures.
• System Reliability: Minimizes downtime by preventing false flame loss signals during peak heating cycles.

Common Technical Questions

What causes a flame rod to fail in a commercial boiler?
Failure is typically caused by carbon fouling, heavy oxidation on the electrode surface, or a hairline crack in the ceramic insulator, which allows the signal to short to ground.

How do I test the 100074673 flame sensor?
Set your multimeter to the DC microamp (µA) scale and wire it in series with the flame rod lead. A healthy sensor usually reads between 2.0 and 5.0 µA depending on the specific ignition module specs.

Can I clean this flame rod instead of replacing it?
While light cleaning with a non-conductive abrasive pad can remove oxidation temporarily, deep pitting or ceramic damage requires a full replacement to ensure commercial boiler safety compliance.

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.