Lochinvar & A.O. Smith 100290350 Rollout Switch

The Lochinvar & A.O. Smith 100290350 Rollout Switch is a mission-critical safety component designed for high-efficiency commercial and residential water heaters and boilers. This manual reset (M/R) thermal switch is calibrated for a 325F trip point, functioning as a fail-safe to interrupt the burner circuit if flame rollout or excessive heat is detected near the burner vestibule. As the direct 100148397 replacement, this updated OEM part ensures precise compatibility with original control strings without requiring modifications. When troubleshooting water heater rollout switch tripping, verifying flue draft and heat exchanger integrity is essential before replacing the 100290350 limit switch. This high-temperature sensor is commonly used in Lochinvar Knight and A.O. Smith Cyclone series units. Ensuring a secure mechanical connection and proper electrical continuity is vital for maintaining the flame safety circuit and preventing nuisance shutdowns in commercial water heating systems.

• Direct OEM Replacement: Seamlessly replaces legacy part number 100148397 for simplified field service.
• Precise Thermal Calibration: Fixed 325-degree Fahrenheit trip point provides reliable protection against flame rollout conditions.
• Manual Reset Design: Requires technician intervention after a trip, ensuring a safety inspection is performed before system restart.
• Durable Construction: Engineered to withstand the high-temperature environment of the burner housing.

What causes a 325F rollout switch to trip?
A trip usually indicates a venting restriction, cracked heat exchanger, or insufficient combustion air causing flames to exit the combustion chamber. The 100290350 must be manually reset after the root cause is addressed.

Is the 100290350 compatible with older Lochinvar models?
Yes, this part serves as the updated technical equivalent for the 100148397. Always verify your specific model and serial number to ensure the 325F rating matches the original equipment manufacturer specs.

Can I bypass this switch for testing?
Bypassing a safety limit is never recommended. If the switch shows no continuity and the burner is cool, the internal bimetal disc has likely deployed, and the part requires manual resetting or replacement.

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.