Lochinvar & A.O. Smith 100208556 Sensor Kit

The Lochinvar & A.O. Smith 100208556 Limit Flue Sensor Kit is a critical OEM replacement component engineered for precise monitoring of exhaust temperatures in high-efficiency heating systems. This flue limit rated sensor acts as a primary safety mechanism, detecting excessive heat within the venting system to prevent heat exchanger damage and ensure professional-grade operational safety. Designed to replace legacy part numbers 100170535 and TST20007K, this kit is vital for maintaining the integrity of condensing boilers and commercial water heaters. It features a high-accuracy thermistor specifically calibrated for the thermal demands of Lochinvar Knight and A.O. Smith Shield series units. By integrating this genuine Lochinvar replacement part, technicians can resolve "flue temperature limit exceeded" errors and prevent unnecessary system lockouts. Its durable construction is built to withstand the corrosive environment of flue gas condensate, providing long-term reliability for Armor wall-mount water heaters and similar hydronic applications.

Key Benefits

• System Protection: Actively monitors flue gas temperatures to trigger safety shutdowns before overheating occurs, protecting the heat exchanger and venting.
• OEM Compatibility: Direct replacement for 100170535 and TST20007K, ensuring perfect fitment and electrical calibration for Lochinvar and A.O. Smith equipment.
• Broad Application: Field-tested for use in SHIELD (SNR126, SNR151, SNR201) and Armor (WA125-200) models.
• Compliance & Safety: Restores factory-spec safety limits required for commercial and residential HVACR system operation.

Common Questions

What boiler models are compatible with the 100208556 sensor?
This sensor kit is primarily used in Lochinvar Knight, Armor (WA125-200), and SHIELD series (SNR/SNA models) water heaters and boilers.

Does this kit replace the old SAP number 100170535?
Yes, the 100208556 is the official cross-reference and replacement for the discontinued 100170535 and TST20007K sensor kits.

What causes a flue limit sensor to trip?
Common causes include scale buildup in the heat exchanger, restricted venting, or a malfunctioning blower assembly, all of which this limit flue sensor is designed to detect to prevent equipment failure.

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.