Lochinvar & A.O. Smith 100208666 Cutoff

The Lochinvar & A.O. Smith 100208666 Low Water Cutoff Manual Reset is a critical safety component designed to protect high-efficiency hydronic systems. As a direct OEM replacement part for WTR2530 and WTR2530K, this probe-type LWCO sensor ensures the burner circuit remains de-energized during low-water conditions, preventing catastrophic heat exchanger failure or "dry firing." Engineered specifically for the Lochinvar Power-Fin series (models PB/PF 502 to 1302) and compatible with Knight heating boilers, this device features a reliable 1/2-inch NPT connection for seamless integration into the boiler shell or external manifold piping.

The manual reset functionality is a strictly required safety feature in many jurisdictions, mandating that a technician inspect the system before operation resumes. By utilizing electrical conductivity, the 100208666 detects water levels with industrial precision, stopping the boiler firing sequence immediately if the probe loses contact with the fluid. This boiler low water cutoff is built to withstand high-pressure environments, ensuring long-term structural integrity and steady signal transmission to the primary control board.

• Precise Conductivity Sensing: Utilizes advanced probe technology to detect water levels without moving parts that can scale or bind.
• Universal OEM Compatibility: Verified to replace WTR2530 and WTR2530K seamlessly in Lochinvar and A.O. Smith commercial units.
• Field-Proven Safety: The manual reset mechanism prevents automatic restarts, ensuring site safety and thorough system diagnostics.
• Industrial-Grade Build: Designed for high-temperature hydronic applications to maintain continuous operational reliability.

What is the difference between this and an automatic reset LWCO?
An automatic reset will restart the burner once water is restored; however, this 100208666 manual reset requires human intervention, satisfying stricter safety codes for commercial heating installations.

How do I troubleshoot a 100208666 lockout?
Verify the system pressure meets a minimum of 12 psi and check for air pockets in the near-boiler piping. If the red indicator light remains on despite the presence of water, clean the probe to remove mineral buildup.

Can I use this on a Lochinvar Knight wall-hung boiler?
Yes, this LWCO manual reset is often used as a secondary safety on Knight series boilers, typically installed in a tee alongside the pressure relief valve on the supply header.

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.