Lochinvar & A.O. Smith 100173054 Inlet Sensor

The Lochinvar & A.O. Smith 100173054 Inlet Sensor is a critical NTC thermistor engineered for precise temperature monitoring in high-efficiency commercial water heaters and hydronic boilers. This sensor, which is cross-compatible and functionally identical to WRE2145, monitors the incoming water temperature to provide real-time data to the control module. This allows the system to modulate the firing rate accurately, maintaining a stable delta T across the heat exchanger and preventing thermal shock or inefficient cycling. Veteran contractors know that a drifting or "shorted" sensor often triggers nuisance Lochinvar error codes or high-limit lockouts, even when the pump and flow are functional.

Constructed with high-quality materials to withstand consistent thermal cycling, the 100173054 ensures that the temperature-to-resistance feedback remains within the tight tolerances required by SMART TOUCH and integrated control boards. Whether you are performing a routine HVAC sensor replacement or troubleshooting a "Delta T High" fault on a 400 FTXL or similar series, using an OEM 100173054 inlet thermistor is essential for restoring factory-standard efficiency and peak system performance.

Key Benefits

• System Accuracy: Delivers precise resistance readings to the control board, preventing inefficient modulation and unnecessary fuel consumption.
• Direct Cross-Reference: 100% compatible with WRE2145, simplifying truck stock for technicians servicing both Lochinvar and A.O. Smith equipment.
• HVAC Reliability: Designed to meet rigid technical specifications for commercial heating environments, ensuring long-term stability without signal degradation.
• Rapid Diagnostics: Helps eliminate false boiler lockout conditions by providing reliable inlet temperature tracking.

Common Questions

Is the 100173054 compatible with the WRE2145?
Yes, these two part numbers represent the same technical component and are interchangeable in all documented Lochinvar and A.O. Smith applications.

How do I troubleshoot an Inlet Sensor Fault on my boiler?
First, verify the wiring harness for continuity. If the wiring is intact, use a multimeter to check the sensor's resistance against the manufacturer’s 10k-ohm (or applicable) thermistor chart. A "shorted" or "open" reading indicates the sensor requires replacement.

Can I use this sensor for outlet temperature monitoring?
While the physical sensor may appear similar, you should always verify the specific part number required for the outlet or flue high-limit application to ensure the resistance curve and temperature range match the system’s programming.

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.