Check the listing for details. Johnson Controls A19DAC-10C Surface-Mounted Single-Stage Temperature Control ^. Condition: Used. Listed at 46.45 USD. Good condition. Item shows signs of wear - residual dirt and scratches. Foam is dry-rotted and copper plate shows signs of wear. Includes: Unit and (2) metal brackets. The Johnson Controls A19DAC-10 (A19DAC-10C) is a surface-mounted, single-stage temperature control designed primarily for fluid piping applications. It's a robust, electromechanical device, not a modern digital thermostat with a display. The A19DAC-10 is commonly used in HVAC and industrial applications for: High Temperature Cutout Control - On boiler applications, it can be set to shut down the heating plant if the water temperature exceeds a safe limit. Low Temperature Cutout Control - On unit heaters, it can prevent the discharge of cold air by activating a fan or heater when the return water temperature is sufficiently high.