The Lochinvar & A.O. Smith 100274592 Lower T-Stat is a critical OEM replacement part designed for high-performance residential electric water heaters. As a direct replacement for the Lochinvar TST1120 and A.O. Smith 100077850, this lower thermostat provides precise thermal sensing to maintain consistent water temperatures and system efficiency. Engineered for durability in high-demand environments, it is compatible with a wide range of models, including the Lochinvar LT, LS, LC, ET, ES, EC, MT, and JR series. This 240V component features a standard mounting bracket for a secure, flush fit against the tank wall, ensuring accurate heat transfer and preventing rapid cycling. For technicians performing electric water heater repair, utilizing this genuine Lochinvar 100274592 ensures the equipment maintains its original specifications and safety standards without the risks associated with universal after-market alternatives. Integration is straightforward for contractors, fitting seamlessly into existing wiring harnesses to restore optimal hot water recovery rates. Key Benefits for HVACR Professionals Exact OEM Compatibility: Serves as the precise replacement for Lochinvar TST1120 and A.O. Smith 100077850, eliminating fitment issues during installation. Broad Series Integration: Validated for use across major residential lines, including Lochinvar LT, LS, LC, and A.O. Smith electric tanks. Enhanced Thermal Sensitivity: Provides specialized lower thermostat calibration to ensure the bottom element activates only when necessary, improving overall energy efficiency. Industrial-Grade Construction: Built to withstand the cycles of 240V residential water heating systems for long-term field reliability. Common Technician Questions How do I confirm if the 100274592 is the correct lower thermostat for my unit? Consult the rating plate on your water heater. This part is the standard lower T-stat replacement for most Lochinvar and A.O. Smith residential electric models, specifically identifying with part numbers 100274592, TST1120, and 100077850. Can this part be used as an upper thermostat? No. This is a lower thermostat designed without the high-limit (ECO) reset found on upper thermostats. For a complete system overhaul, ensure you are matching the lower and upper controls to their specific designated roles. What are the electrical requirements for this control? This is a standard 240V control designed for residential electric heater circuits. Always verify that power is disconnected at the circuit breaker before attempting to slide the unit into its bracket and reconnecting the wiring harness. 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.
