Lochinvar & A.O. Smith 100109448 Valve

When you are out on a service call for a standard residential or commercial hot water system, the Lochinvar & A.O. Smith 100109448 is a critical safety component you need to have on the truck. This 3/4" temperature and pressure relief valve is engineered to meet specific ASME and AGA standards, providing a set 150 PSI relief pressure and a mandatory 210°F temperature relief. With a thermal discharge capacity of 105,000 BTU/hr, this T&P valve effectively manages thermal expansion and prevents dangerous over-pressurization in water heaters and storage tanks. This specific OEM replacement part features a 2.3-inch probe length, ensuring accurate thermal sensing within the top six inches of the tank, where the hottest water accumulates.

Key Benefits

• Dual-Action Protection: Monitors both system pressure and water temperature to prevent tank rupture or scaling conditions.
• Precision Engineering: Direct Lochinvar and A.O. Smith replacement ensures 3/4" NPT threading matches the factory-designated opening for a leak-free seal.
• High Thermal Capacity: Rated for 105,000 BTU, making it suitable for a wide range of gas and electric water heating applications.
• Robust Construction: Built for HVAC technician standards to withstand the rigorous demands of commercial and residential hydronic systems.

Common Questions

What is the relief set point for the 100109448 valve?
This valve is factory-calibrated to discharge at 150 PSI or when the internal water temperature reaches 210° Fahrenheit.

Why is the 2.3-inch probe length important?
The probe must sit within the hottest area of the tank to function correctly. This length is standard for many A.O. Smith and Lochinvar units to ensure the sensor accurately detects when the system exceeds safety limits.

Can I use this on a boiler system?
Yes, provided the boiler’s BTU output does not exceed the valve’s 105,000 BTU/hr capacity and the system operating pressure is below the 150 PSI rating.

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.