Lochinvar & A.O. Smith 100112662 High Limit

The Lochinvar & A.O. Smith 100112662 High Limit is a critical OEM safety control designed to prevent terminal damage in high-output commercial and residential heating systems. Engineered for hydronic boilers and gas water heaters, this 165-degree limit switch monitors internal temperatures and breaks the electrical circuit if limits are exceeded. As a manual reset safety switch, it requires technician intervention to investigate the root cause of an overheat lockout, ensuring that HVAC systems do not cycle under unsafe conditions.

Built for durability in industrial heating applications, the 100112662 switch maintains precise temperature calibration to satisfy UL safety requirements for Lochinvar Knight and A.O. Smith Cyclone series units. This high-limit cutout is essential for replacing worn bimetal sensors that exhibit nuisance tripping or failure to reset. Its compact design allows for direct mounting on the heat exchanger outlet or tank assembly, providing rapid response to thermal excursions and protecting both the heat exchanger and the combustion system.

• Circuit Protection: Immediately interrupts the ignition control circuit to stop firing when outlet temperatures reach the 165°F setpoint.
• OEM Compatibility: Exact Lochinvar and A.O. Smith replacement part for guaranteed fitment in Armor X2, Power-fin, and residential gas water heaters.
• Manual Reset Mechanism: Enhances boilers and furnace safety by preventing automatic restarts after a high-limit trip.
• Thermal Accuracy: High-sensitivity bimetal sensing element provides consistent performance across commercial heating cycles.

Common Questions:

How do I troubleshoot a persistent 100112662 lockout?
A recurring trip usually points to low water flow, pump failure, or a clogged heat exchanger. Check the circulator pump and verify that the system air has been fully purged before replacing the limit switch.

Can I swap a manual reset with an automatic reset switch?
No. Manual reset limits are a mandatory safety requirement for specific HVACR equipment. Installing an automatic reset where a manual is specified can lead to dangerous short-cycling and potential component failure.

What is the maximum operating temperature for this part?
This specific high-limit switch is calibrated to open the circuit at 165°F (74°C) to protect against excessive water temperatures in the tank or outlet piping.

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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.