Lochinvar & A.O. Smith 100108455 Valve

The Lochinvar & A.O. Smith 100108455 is a critical safety component designed for residential water heating systems, including direct vent models. As a veteran-grade temperature and pressure relief valve (T&P), it protects the tank from catastrophic failure by monitoring and relieving excess internal energy. This genuine OEM replacement part features a 2-inch shank length designed to penetrate the insulation of 2-inch cavity heaters, ensuring the sensing element is properly immersed in the water for accurate thermal response. Equipped with a standard 3/4" male NPT connection, this valve is engineered for a 150 PSI pressure rating and a thermal relief threshold of 210°F.

For contractors performing water heater maintenance, installing a high-quality brass construction relief valve is essential to prevent discharge leaks caused by thermal expansion. This model, also identified as the TP-102, provides a reliable seal and precise blow-down performance. When diagnosing a leaking T&P valve, it is vital to verify the system's static pressure and ensure a functional expansion tank is in place, as these valves are designed to trigger during over-pressurization events to maintain vessel integrity.

• Precise Thermal Response: The 2" element ensures the probe reaches past the tank insulation into the water stream for accurate 210°F sensing.
• Heavy-Duty Brass Construction: Manufactured with corrosion-resistant brass to withstand high-temperature residential potable water environments.
• Universal Compatibility: Fits a wide range of Lochinvar, A.O. Smith, State, and American Water Heater residential models.
• Safety Compliance: Rated at 150 PSI to meet standard code requirements for residential water heater safety.

Why is the T&P valve dripping even when the water isn't overheating?
A dripping 100108455 valve often indicates excessive system pressure or thermal expansion issues rather than a faulty seat. Check if the home requires a pressure reducing valve (PRV) or if the existing expansion tank has a ruptured bladder.

Can I use this on a commerical high-recovery unit?
This specific 3/4" T&P valve is primarily designed for residential orientations. Always verify the BTU discharge capacity (AGA/ASME rating) on the original valve's tag matches the 100108455 specifications before installation.

Does the 2" shank length matter for the install?
Yes. The 2" shank is required for heaters with thicker insulation blankets to ensure the temperature sensing probe is correctly positioned. Using a shorter shank may result in delayed activation, compromising safety.

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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.