Lochinvar & A.O. Smith 100108899 Limit Switch

The Lochinvar & A.O. Smith 100108899 Limit Switch is a critical safety component designed for high-performance HVAC equipment and water heating systems. Engineered for precision, this L200F manual reset high limit switch monitors internal temperatures and executes a high temperature shutdown if the system exceeds the 200°F safety threshold. By interrupting the electrical circuit during an overheat event, it prevents damage to the heat exchanger and ensures the integrity of residential and commercial boiler systems.

Built for durability in demanding environments, this OEM replacement part is compatible with specified Lochinvar and A.O. Smith models. As a manual reset limit switch, it requires a technician to physically inspect the system and manually reactivate the control, ensuring that underlying issues—such as restricted airflow or scale buildup—are addressed before resuming operation. This switch is a direct solution for restoring the safety circuit in mid-efficiency and high-efficiency heating units.

• Precise Thermal Protection: Set to trigger at 200 degrees Fahrenheit to prevent catastrophic overheating.
• Manual Reset Safety: Forces a system check after a trip event, preventing hazardous HVAC troubleshooting cycles.
• Reliable OEM Fit: Ensures seamless integration with A.O. Smith water heaters and Lochinvar boilers.
• Industrial-Grade Construction: Designed to withstand the thermal stresses of high-duty cycle heating applications.
• Enhanced System Logic: Effectively communicates with the ignition control board to lock out the burner during unsafe conditions.

What causes this limit switch to trip frequently?
Frequent tripping usually indicates restricted water flow, excessive scale in the heat exchanger, or a malfunctioning primary thermostat. Always verify pump operation and system pressure after a trip.

Can I use this as an automatic reset switch?
No, this is an L200F manual-reset safety device. It is specifically designed to remain open until a technician manually resets it to ensure the system is safe for operation.

Is this switch compatible with other 200-degree applications?
While it triggers at 200°F, compatibility is determined by the mounting footprint and terminal configuration. Always cross-reference the 100108899 part number with your specific model data.

This item is not eligible for free shipping.

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.