Rheem-Ruud 47-21711-04 Limit Switch

When you're dealing with a furnace that's tripping on high limit, you need a reliable Rheem-Ruud 47-21711-04 Limit Switch to ensure the system stays within safe operating parameters. This OEM Rheem replacement part is a board-mounted general purpose limit switch designed with a 7-inch insertion length, making it a drop-in fit for specific air handler and furnace configurations. Operating as a normally closed (SPST) switch, it provides critical overheat protection by opening the circuit at a fixed open temperature of 200°F. Once the heat exchanger or plenum cools down to the fixed close temperature of 180°F, the auto reset function restores continuity. This high-limit safety control is essential for preventing structural damage and ensuring HVAC system safety. Built to withstand industrial-grade thermal cycling, this 47-21711-04 furnace limit switch ensures your client's equipment remains operational without the nuisance tripping associated with lower-quality aftermarket sensors.

• Precise Thermal Calibration: Factory-set for a 200°F trip and 180°F reset to maintain optimal furnace safety.
• Extended 7" Reach: The long insertion probe allows for accurate temperature sensing deep within the airflow path.
• OEM Compatibility: Authentic Rheem-Ruud 47-21711-04 engineering ensures exact electrical and mounting alignment.
• Automated Recovery: Featuring an auto-reset mechanism that eliminates the need for manual intervention after a cooling period.

• What causes this limit switch to trip frequently? Frequent tripping usually indicates restricted airflow due to a dirty filter, failing blower motor, or blocked ductwork rather than a faulty 47-21711-04 switch.
• Is this switch compatible with other brands? While primarily designed for Rheem, Ruud, and WeatherKing equipment, always cross-reference the 200/180 degree spec and the 7-inch insertion depth.
• How do I test if the SPST switch is defective? Use a multimeter to check for continuity across the terminals at room temperature; since it is normally closed, it should show a closed circuit unless the temperature exceeds 200°F.

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.