Lochinvar & A.O. Smith 100208553 Sensor

As a seasoned technician, you know that accurate temperature regulation is the heartbeat of high-efficiency hydronic systems. The Lochinvar & A.O. Smith 100208553 Sensor is a critical OEM replacement part designed for precision thermal monitoring in commercial boilers and water heaters. This immersion inlet sensor provides real-time resistance feedback to the control module, ensuring the system maintains optimal firing rates and prevents overheating. Engineered to be identical to TST2050 and TST2050K, this component is a drop-in solution for Lochinvar Copper-Fin II models (CB/CW 987-2067) and EnergyRite pool heaters. When your Lochinvar boiler troubleshooting points to erratic temp readings or sensor open/shorted codes, swapping in this heavy-duty NTC thermistor restores the aquastat control accuracy required for peak performance. Its 1/4" NPT threading and durable probe construction are built to withstand constant exposure to system fluids, making it a reliable choice for HVAC contractors who demand exact Lochinvar replacement parts to keep high-demand facilities up and running without unexpected lockouts.

• Direct OEM Compatibility: Replaces TST2050, TST2050K, and 100170591, ensuring seamless integration with existing terminal wiring and control logic.
• Precision Thermal Data: High-accuracy resistance-type sensor provides the exact inputs needed for the control module to regulate modulation and blower speed.
• Heavy-Duty Immersion Design: Built to handle the high-cycle demands of commercial water heaters and large-scale Copper-Fin II hydronic boilers.
• Critical Safety Integration: Prevents unsafe operating conditions by alerting the system to potential inlet temperature hazards and high-limit differentials.

What are the signs that my immersion sensor needs to be replaced?
Technicians typically look for E19 or E21 fault codes on the Smart Touch interface, or wildly fluctuating inlet temperature readings that cause the burner to cycle prematurely. If ommeter readings across the sensor leads don't match the manufacturer’s resistance chart, the 100208553 sensor must be swapped.

Is this sensor compatible with both boilers and pool heaters?
Yes, this 100208553 inlet sensor is the standard 1/4" NPT immersion kit for several large-scale units, including the Lochinvar EnergyRite pool heater series and the Copper-Fin II commercial boiler line.

Can I use this as an outlet sensor replacement?
No, while the construction is similar, the control module expects specific resistance curves from the inlet sensor position. Using the wrong part number can lead to improper modulation and potential system lockouts.

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.