Bradford White 415-43676-03 Thermal Switch

The Bradford White 415-43676-03 Thermal Switch is a critical safety component designed for atmospheric vent gas water heaters and Defender Safety System models. This L290F reset thermal switch operates as a secondary high-limit safety, engineered to interrupt the electrical or thermocouple circuit if internal temperatures exceed 290 degrees Fahrenheit. As a veteran-grade OEM replacement part, the 415-43676-03 ensures the integrity of the combustion chamber by preventing overheating conditions that could lead to system damage or safety hazards.

This manual reset thermal switch is the direct factory authorized replacement for legacy part numbers 239-43676-03 and 100167474. Featuring a distinct red housing for quick field identification, the switch utilizes standard 1/4-inch quick-connect terminals for seamless integration into existing harnesses. This component is frequently used in Bradford White MI30T, MI303T, and MI40T residential series. For HVACR professionals, verifying the underlying cause of a trip—such as restricted airflow or burner malfunction—is essential before utilizing the manual reset button to restore operation.

• Direct OEM Compatibility: Engineered specifically for Bradford White flammable vapor ignition resistant (FVIR) systems, ensuring precise fitment and electrical calibration.
• High-Temperature Calibration: The 290°F trip point provides a reliable safety threshold for high-tolerance residential and commercial water heating applications.
• Resettable Design: Features a manual reset button, allowing technicians to restore system function once the thermal excursion cause is diagnosed and corrected.
• Simplified Identification: Color-coded red thermal switch housing prevents installation errors with lower-temperature blue or yellow limit counterparts.

Why does the L290F thermal switch keep tripping?
Frequent tripping usually indicates poor combustion air supply, a clogged flame arrestor, or venting issues. Always inspect the water heater burner chamber for lint or dust accumulation before resetting.

Can I substitute this with a 240F or 270F switch?
No. Swapping the 415-43676-03 with a different temperature rating will compromise the safety logic of the gas control valve and may lead to premature shutdowns or hazardous operating conditions.

Is this switch compatible with the Honeywell burner assembly?
Yes, this reset thermal switch is the standard component for many Honeywell-equipped Bradford White atmospheric units requiring an L290F limit.

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.