Lochinvar & A.O. Smith 100074624 Valve

For veteran contractors managing high-efficiency hydronic systems, the Lochinvar & A.O. Smith 100074624 is a critical OEM component that serves dual functions as a flow adjustment valve and an integrated flow sensor. Engineered specifically for Lochinvar Knight and A.O. Smith tankless units, this valve provides the precise regulation necessary to maintain optimal delta T across the heat exchanger. By accurately monitoring and modulating fluid velocity, it helps prevent short-cycling and localized overheating, which are common causes of premature component stress in condensing boilers and volume water heaters.

This genuine OEM replacement part is built for the demanding environments of commercial and residential HVACR applications. The 100074624 flow sensor valve integrates seamlessly with the appliance’s control board, delivering real-time data to ensure the system only fires when adequate flow is detected—a vital safety protocol for protecting the stainless steel heat exchanger. Replacing a fouled or sticking valve with this factory-authorized part restores the system's ability to balance Domestic Hot Water (DHW) priority and space heating loops with high-accuracy calibration.

Technical Benefits:

• Optimized System Efficiency: Maintains precise GPM flow rates to maximize heat transfer and condensing performance.
• Integrated Safety Monitoring: The built-in flow sensor provides immediate feedback to the control module to prevent "dry fire" or low-flow lockouts.
• Direct OEM Compatibility: Designed for an exact fit in Lochinvar and A.O. Smith equipment, eliminating the need for field modifications.
• Durable Construction: High-grade materials resist mineral buildup and corrosion in closed-loop and potable water systems.

Common Questions:

Does this valve solve "Flow Switch" lockout codes?
Yes, if the control board is throwing persistent flow-related errors and the pump is verified operational, the integrated 100074624 sensor may be failing to send a correct signal, requiring a direct replacement.

Is the flow sensor available separately?
The 100074624 is a complete assembly. For reliable field performance and to ensure the flow adjustment mechanism is properly calibrated with the sensor, it is recommended to replace the entire unit.

What causes these valves to fail?
Most failures are due to sediment buildup or moisture intrusion into the sensor housing. It is a standard practice for technicians to inspect this valve during annual boiler maintenance to ensure the internal paddle or turbine moves freely.

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.