Lochinvar & A.O. Smith 100210102 Limit Switch

The Lochinvar & A.O. Smith 100210102 Limit Switch is a critical safety component designed for high-efficiency boilers and commercial water heaters. This OEM hi limit switch acts as a fail-safe by monitoring internal temperatures and interrupting the power supply to the burner or fan if the system exceeds its safe operating ceiling, typically around 145 degrees depending on the specific series configuration. Engineered for high-demand environments, this 100210102 replacement ensures thermal protection and prevents heat exchanger damage caused by overheating or poor water flow.

When you encounter a "Lock Out Man Rst Hi Limit" error on a Lochinvar Knight boiler or A.O. Smith power vent unit, verifying the limit switch continuity is a standard diagnostic step. This boiler safety control is compatible with a wide range of residential and commercial systems, including the Power Vent Water Heater Series 200, 300, and 304. Installing this genuine 100210102 high limit helps maintain the system's UL compliance and operational integrity without the risks associated with universal counterparts.

Key Benefits:

• Precise Thermal Cutout: Factory-calibrated to trigger at 145°F to prevent equipment failure and ensure user safety.
• Broad Compatibility: Fits various Lochinvar and A.O. Smith models, including Knight boilers and Power Vent water heaters.
• Optimized System Protection: Prevents scale build-up and localized hotspots from causing catastrophic heat exchanger cracks.
• OEM Standards: Direct-fit replacement ensures correct electrical impedance and mounting for the sensor probe or surface mount.

Common Questions:

• Does this limit switch require a manual reset? Many applications for the 100210102 function as a manual reset safety; if it trips, the technician must investigate flow issues or scale before resetting the control.
• What causes a high limit switch to trip repeatedly? Common culprits include a failing circulator pump, air trapped in the heat exchanger, or a restricted water-side internal assembly.
• Is this part compatible with my specific serial number? While this part fits numerous series including 200/201/202 and 300/301/304, always verify your specific model data before installation.

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.