Lochinvar & A.O. Smith 100108422 Thermostat

The Lochinvar & A.O. Smith 100108422 Thermostat is a critical lower electric water heater thermostat designed for precise temperature regulation in residential applications. As a genuine OEM replacement part, this WH9 model features a dual-pole connection compatible with voltages ranging from 208V to 480V. It is engineered to maintain thermal stability by managing the lower heating element, ensuring optimal energy efficiency and consistent recovery rates. This unit includes a high-limit Safety Energy Cut Off (E.C.O.), which disconnects power if the internal tank temperature exceeds 190°F, providing essential protection against overheating. The manual dial allows for service adjustments between 110°F and 160°F, pre-set from the factory at 120°F. Supplied with a protective cover, this thermostat is built to replace legacy components like the 9000507045, 7025, and WH7, making it a versatile water heater repair part for a wide range of A.O. Smith and Lochinvar electric tanks.

Key Benefits

• Broad Compatibility: Directly replaces multiple part numbers including 9000507045, 8025, and WH5 across Lochinvar, A.O. Smith, and State Industries units.
• Enhanced Safety: Integrated Energy Cut Off (E.C.O.) manually resets and prevents tank failure due to runaway heating.
• Durable Infrastructure: Includes a high-grade plastic thermostat cover to shield 2-pole electrical terminals from debris and moisture.
• Technical Precision: Allows for field-adjustable temperature settings to meet specific commercial or residential thermal requirements.

Common Questions

Is this thermostat compatible with 240V residential systems?
Yes, the 100108422 is rated for 208V through 480V applications, making it the standard choice for 240V electric water heaters.

Does this part replace the upper or lower thermostat?
This is a lower thermostat specifically designed to regulate the secondary heating element in dual-element water heaters.

What is the difference between this and the 9000507?
This model includes the WH9 configuration with an integrated E.C.O. and cover, providing a higher level of safety and protection for the lower element circuit.

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.