Lochinvar & A.O. Smith 100208462 Flame Rod

The Lochinvar & A.O. Smith 100208462 Flame Rod is a critical safety component designed for flame rectification in high-efficiency boilers and commercial water heaters. This 9-inch K. Holder flame sensor (identical to the RLY2705) monitors the burner's combustion process by generating a DC microamp (µA) signal. When the control board detects the correct ionization current—typically between 8.0 µA and 12.0 µA—it "proves" the flame and allows the gas valve to remain open. If the signal drops below the 1.0 µA threshold due to carbon buildup or oxidation, the system triggers an ignition failure lockout to prevent unburned gas accumulation.

As a direct OEM replacement for Lochinvar boiler parts and A.O. Smith water heaters, this 100208462 flame rod ensures precise sensing and seamless integration with existing burner assemblies. Its stainless steel construction and high-grade ceramic insulator are engineered to withstand the rigorous thermal environment of a radial fire burner. Technicians should verify proper appliance grounding and supply polarity during installation, as a poor ground path can disrupt the small DC current necessary for the hot surface ignition or intermittent pilot system to function reliably.

• Precise Flame Detection: Engineered for accurate burners flame sensing to eliminate nuisance "No Flame" fault codes.
• OEM Compatibility: Replaces RLY2705 and 100208462 with exact factory tolerances for Lochinvar and A.O. Smith applications.
• Reduced System Downtime: Resolves common ignition failure lockouts caused by corroded or fouled sensing rods.
• Enhanced Safety: Essential for preventing hazardous gas buildup by ensuring the gas supply shuts off immediately if the flame is lost.

How do I know if my 100208462 flame rod needs to be replaced?
If your unit ignites briefly but shuts down after a few seconds, the flame sensor likely has soot buildup or an internal crack in the insulator. You can test this with a multimeter in series; if the current is below 1.0 µA while the flame is touching the rod, it is time for a replacement.

Can I clean the flame sensor instead of replacing it?
While light cleaning with ultra-fine steel wool can remove temporary oxidation, the 100208462 is a wear item. Once the rod’s surface or ceramic insulator is compromised, replacement is the only way to ensure reliable flame rectification and prevent future emergency service calls.

Is the 100208462 the same as the RLY2705?
Yes, these part numbers are identical and interchangeable. They share the same 9-inch technical specifications and mounting requirements for compatible Lochinvar and A.O. Smith heating systems.

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.