Resettable Thermal Switch, 240 Degree, Blue

Bradford White 415-43676-01 – Resettable Thermal Cutoff Switch for MI Series Gas Water Heaters

The Bradford White 415-43676-01 is a factory-authorized resettable thermal switch designed to limit temperature rise in select atmospheric vent gas water heaters. Engineered for models such as MI30SF and MI40TF, this component provides an additional layer of over-temperature protection by interrupting power to the gas control valve in the event of abnormal heat levels within the combustion chamber or flueway.

Application and Operation

This switch is calibrated to trip at 240°F and is manually resettable via an integrated push-button. It mounts directly to the exterior jacket of compatible tank models and interfaces with the system’s safety circuitry. Upon detecting a temperature excursion beyond safe limits, the switch breaks the circuit to prevent burner operation, reducing the risk of tank or control damage.

Technical Specifications

• Part Number: 415-43676-01
• Type: Manually resettable thermal switch
• Set Point: 240°F (± tolerance per factory specification)
• Function: Over-temperature safety cutoff
• Mounting: Surface-mounted; includes factory hardware
• Lead Termination: Quick-connect spade terminals
• Compatibility: Bradford White MI30SF and MI40TF models (check unit data tag or service bulletin for confirmation)

Installation Notes

This component should only be installed by trained personnel familiar with residential gas water heater operation and combustion safety controls. When replacing the thermal switch, verify the integrity of the flue baffle, burner chamber, and airflow paths. A tripped switch may indicate a deeper issue, such as a blocked vent or combustion restriction, and should be diagnosed accordingly.

Contractor Recommendations

• ✔ OEM Certified: Always use the exact replacement model to ensure system safety and UL compliance.
• ✔ Quick Reset Design: Enables service restoration without part replacement in non-recurring fault conditions.
• ✔ Field-Proven Reliability: Frequently used during maintenance or troubleshooting of flue gas temperature or venting issues.

Best Practices

Before resetting or replacing this switch, clear any accumulated debris, inspect for proper air intake, and confirm draft performance. If the switch continues to trip under normal operating conditions, verify that the tank insulation, combustion air supply, and flue system are functioning as designed.