Key Benefits Direct OEM Replacement: Replaces HH79NZ037 and HH79NZ003 with exact electrical specifications for plug-and-play installation

Always verify the shaft diameter and voltage before installation to ensure a proper match with your specific unit

it can be used with any thermostat that fits within its 3-7/8" x 3-1/2" x 2-1/2" interior clearance

making it compatible with most residential furnace control boards

Lochinvar & A.O. Smith 100170640 Thermostat Control 320735-701 Key Benefits Direct OEM Replacement:As a veteran tech, you know that maintaining thermal safety is non negotiable for commercial boiler and water heater uptime. The Lochinvar & A. O. Smith 100170640 Thermostat Control is a critical high limit thermostat engineered to provide precise over temperature protection in Lochinvar boilers and high recovery water heating systems. This genuine OEM temperature limit switch serves as a direct replacement for the obsolete Lochinvar TST30009,