Lochinvar & A.O. Smith 100274615 T-Stat

Ensure consistent performance in residential and light commercial electric water heaters with the Lochinvar & A.O. Smith 100274615 T-Stat. This upper thermostat replacement is engineered for high-demand environments, featuring surface mount sensitivity and a built-in manual reset high-limit safety switch (ECO). Designed to handle non-simultaneous operation, this component acts as the primary controller, prioritizing top-tank heating before transferring power to the lower element. The 100274615 is the manufacturer-designated direct replacement for 100077849 and TST1119, ensuring precise terminal alignment for all 2 & 3 wire interconnections. Technicians can rely on its Double Throw (SPDT) action to maintain narrow temperature differentials, preventing rapid cycling and protecting heating elements from premature failure. Compatible with Lochinvar LT, LS, LC, ET, ES, EC, MT, and JR models, this line voltage thermostat is critical for restoring system efficiency and preventing lukewarm water issues caused by faulty signal switching between elements.

• Universal Field Replacement: Direct drop-in for Lochinvar 100077849 and TST1119, eliminating the need for wiring modifications in existing 2-wire or 3-wire configurations.
• Reliable High-Limit Protection: Integrated Energy Cut-Off (ECO) safety circuit protects the tank and piping by interrupting power if temperatures exceed safe operating parameters.
• Broad Compatibility: Fits a wide range of A.O. Smith and Lochinvar residential electric units, including standard and high-capacity commercial-grade models.
• Precise Temperature Control: Heavy-duty electrical contacts provide accurate upper element regulation, ensuring hot water availability at the top of the tank for immediate use.

• Will this work if my current wiring uses three leads? Yes, the 100274615 is designed as an interchangeable upper thermostat that supports both 2-wire and 3-wire interconnection circuits commonly found in non-simultaneous heating systems.
• How do I know if the upper thermostat is the issue? If you have no hot water at all or only a very small amount of lukewarm water, the upper thermostat has likely failed to energize the first element or its high-limit reset has tripped due to an overheat condition.
• Does this include the high-limit reset button? Yes, this unit features the red manual reset button which acts as a secondary safety against tank overheating.

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.