Weil McLain 510-312-150 Operating Limit

The Weil McLain 510-312-150 Operating Limit is a professional-grade combination operating limit and fixed high limit temperature control engineered for hydronic heating systems. This dual-function component is a primary safety and control interface for Weil-McLain EG, EGH, and PFG boilers, specifically optimized for sizes 85 and 95. It features a versatile operating temperature range of 140°F to 240°F and a factory-set fixed high limit at 240°F to prevent thermal runaway. Utilizing a DPST (Double Pole Single Throw) switch with automatic recycle logic, this limit ensures consistent cycling without manual intervention. The unit includes a 3/4 inch immersion well and is furnished with wire leads designed for direct connection to thermocouple spade terminal blocks. For seasoned contractors, this OEM replacement part provides the exact electrical matches and thermal response curves required for gas-fired water boiler maintenance and boiler safety control upgrades, maintaining the mechanical integrity of the original installation.

Key Benefits:

• Broad Compatibility: Precise fit for Weil-McLain EG, EGH, and PFG series boilers, ensuring consistent boiler temperature control.
• Dual-Function Protection: Merges operating limit functionality with a fixed high limit for redundant system safety.
• Efficient Switching: Features a DPST switch design for reliable electrical interruption during high-limit events.
• Installation Ready: Provided with a 3/4 inch well and wire leads to streamline field replacements.

Common Questions:

What is the maximum temperature setting for the 510-312-150?
The fixed high limit is set at 240°F, while the operating limit allows for adjustments within the 140°F to 240°F span.

Does this unit require a manual reset?
No, this model features automatic recycle, which allows the switch to reset itself once the water temperature drops below the differential setting.

Which boiler models use this limit control?
It is primarily designed for Weil-McLain EG, EGH, and PFG boilers, specifically sizes 85 and 95.

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.