Marley Engineered Products 410027000 Limit Switch

As a field technician, you know that the safety of a heating system hinges on reliable high-limit controls. The Marley Engineered Products 410027000 Limit Switch is a critical OEM replacement hi-limit switch designed for QMark and Berko unit heaters. This L275-50F automatic reset limit switch features a T-O-D Therm-O-Disc bimetal mechanism that triggers at 275°F and restores the circuit once the environment cools to 225°F. With its distinctive blue and white label, this SPST furnace safety control ensures precise over-temperature protection for industrial HVAC equipment. Replacing a failed switch with this genuine Marley component maintains the factory-specified safety parameters and ensures compatibility with units such as the UH520, UH524, and UH538 series.

Key Benefits:

• Precise Safety Cut-Out: Pre-set to open at 275°F and close at 225°F to prevent heat exchanger damage or hazardous operation.
• Automatic Reset Logic: Eliminates the need for manual intervention once temperatures return to safe operating levels.
• Universal Application: Cross-compatible with Marley, Berko, and QMark heating systems using the 410027-000 or 60TX21 part numbers.
• Rugged Build: High-tolerance bimetal disc construction offers long-term switching cycles in demanding industrial environments.
• Exact OEM Fit: Designed to meet original factory specifications for 1.2" depth and 2.3" width mounting footprints.

Common Questions:

• Does this switch require a manual reset button? No, this is an automatic reset limit switch which reconnects power once the ambient temperature drops 50 degrees from the trip point.
• How do I identify this part on an existing unit? Look for the blue/white label and the marking L275-50F on the Therm-O-Disc housing.
• Is this compatible with 240V systems? Yes, as a genuine OEM part for Berko/QMark UH heaters, it is designed for standard control circuit voltages within these units.

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.