Weil McLain 383-500-601 Temperature Sensor

As a seasoned technician, you know that keeping a hydronic system in check starts with reliable data feeding into the control module. The Weil McLain 383-500-601 is a high-precision system temperature sensor designed as a direct replacement component for Ultra Gas and commercial boiler units. This 12k Ohm resistance NTC sensor provides the real-time thermal feedback required for proper mod-con operation, ensuring the boiler control module can accurately adjust firing rates based on actual supply or return temperatures. While many residential setups utilize a single sensor, larger Ultra Gas 550/750 models often require two of these units to monitor both sides of the loop effectively. Built for durability in high-demand mechanical rooms, this sensor eliminates the erratic readings associated with aged or failing probes, preventing premature cycling and ensuring optimal energy management. For contractors performing a mid-season teardown or troubleshooting a "no-heat" call, having a genuine 383-500-601 on the truck is essential for restoring system communication and efficiency.

• System Compatibility: Engineered specifically for the Weil McLain Ultra Gas series and various commercial hydronic boilers.
• Operational Efficiency: Delivers precise 12k Ohm resistance signals to the control board to optimize fuel consumption and modulation.
• Critical Redundancy: Vital for Ultra Gas 550/750 boilers which utilize dual-sensor configurations for balanced thermal monitoring.
• Rugged Construction: Designed to withstand the thermal cycling and humidity levels found in industrial and residential boiler jackets.

• Does this sensor work for both supply and return lines? Yes, the 383-500-601 is used for both supply and return temperature sensing depending on how it is mapped to the boiler's control terminals.
• Will this fix a lockout on an Ultra Gas boiler? If your system is throwing a sensor-related fault code or reporting "Open Circuit" for temperature, replacing the sensor often resolves the communication break between the loop and the control module.
• Is this the same as an outdoor reset sensor? No, this is an internal system sensor; outdoor sensors use different resistance curves and housing.

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.