Lochinvar & A.O. Smith 100109978 Ignitor Assembly

The Lochinvar & A.O. Smith 100109978 Ignitor Assembly is a mission-critical OEM component designed for precise ignition and flame rectification in high-efficiency commercial gas water heaters and boilers. As a genuine 100109978 replacement part, this assembly integrates a high-durability igniter element and flame sensor, a common configuration in the A.O. Smith BTN Series and various Lochinvar heating systems. For technicians out in the field, this part is the primary solution for resolving "no-ignition" lockout codes or inconsistent flame-sense signals that plague older heating cycles. This specific hot surface ignitor is engineered to withstand the thermal stress of rapid cycling, ensuring the burner ignites safely and maintains a stable flame throughout the heating demand. By utilizing this HVAC part 100109978, you maintain the original equipment's combustion integrity and prevent the common nuisance of carbon buildup often seen with generic aftermarket alternatives. It serves as the direct 9004606205 cross-reference updated version, ensuring seamless fitment for models ranging from 120 through 400/A BTN commercial gas units.

• Direct OEM Compatibility: Engineered specifically for Lochinvar and A.O. Smith BTN series models, providing a plug-and-play fit without field modifications.
• Integrated Flame Sensing: Combines ignition and flame detection in a single assembly to streamline the combustion sequence and simplify troubleshooting.
• Optimized Combustion Safety: Built to factory specifications to ensure consistent burner light-off, reducing the risk of delayed ignition or gas accumulation.
• Superior Thermal Resistance: Manufactured with materials designed to endure extreme furnace temperatures, preventing premature element failure.

What models are compatible with this ignitor?
This assembly is primarily utilized in A.O. Smith BTN commercial gas water heaters and compatible Lochinvar boiler units. It frequently supports models 120, 154, 180, 199, 200/A, and up to 400/A.

Does this part replace number 9004606205?
Yes, the 100109978 is the current manufacturer-recommended replacement for the legacy part number 9004606205.

Can I use this for a residential water heater?
While it fits certain high-output residential/commercial hybrid units, it is specifically designed for the commercial-grade BTN Series and should only be installed where the manual specifies this exact part number.

This item is not eligible for free shipping.

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.