Weil McLain 510-312-250 Limit Switch

The Weil-McLain 510-312-250 High Limit Temperature Control is a critical safety component designed for precise thermal regulation in hydronic heating systems. This aquastat replacement operates on an auto-recycle logic, ensuring the burner circuit interrupts when water temperature hits the high-limit setpoint to prevent boiler overheating. It features an adjustable temperature range of 140°F to 240°F and utilizes a 30°F fixed subtractive differential, providing a reliable buffer to prevent short-cycling of the heating equipment. Engineered for seamless integration, this Weil-McLain boiler part includes a 1/2" NPT immersion well for direct mounting into the heat exchanger or manifold. As a direct replacement for 510-312-254, this control simplifies field service by maintaining the original footprint and electrical terminal configurations. This HVAC high limit switch is essential for technicians addressing Weil-McLain limit switch troubleshooting or standard preventative maintenance on cast iron boiler blocks.

• Broad Compatibility: Serves as the functional successor to the 510-312-254 model, ensuring drop-in installation without piping modifications.
• Precise Thermal Cutout: The adjustable 140-240°F range allows for fine-tuning based on specific system demand and ambient conditions.
• Durable Construction: Features a robust immersion well design capable of withstanding standard hydronic system pressures and chemical treatments.
• Operational Efficiency: The fixed 30°F subtractive differential stabilizes burner cycles, reducing mechanical wear on the primary ignition control.

What is the difference between this model and the 510-312-254?
The 510-312-250 is the current manufacturing standard and direct replacement for the older 510-312-254, maintaining identical electrical ratings and physical dimensions.

Is the immersion well included with this temperature control?
Yes, this unit ships with a standard 1/2" NPT well to ensure proper thermal contact and a leak-free seal within the boiler tapping.

How does the auto-recycle function operate?
Once the water temperature drops below the high-limit setpoint (minus the 30°F differential), the control automatically closes the circuit to allow the burner to fire again without a manual reset.

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.