Johnson Controls A19ADB-31 Utility Thermostat, 120/208/240V, 90–325°F, Manual Reset

The Johnson Controls A19ADB-31 is a heavy-duty utility thermostat engineered for demanding commercial and industrial HVAC and process-control applications. Featuring a wide 90°F to 325°F temperature sensing range, this thermostat is well-suited for high-temperature monitoring in boilers, heat exchangers, duct systems, and other process equipment where precise thermal control is critical.

Electrical & Sensing Specifications

• Voltage Rating: 120/208/240 VAC
• Temperature Range: 90°F to 325°F
• Capillary Length: 10 feet for flexible remote sensing installation
• Remote Bulb Dimensions: 0.29″ diameter x 2.5″ length
• Action: Open on temperature rise (Open Hi)

Control & Safety Features

• Manual Reset — requires deliberate operator action to restore operation after a high-temperature trip, providing an added layer of safety
• Enclosed setpoint adjustment for tamper-resistant, secure calibration
• Includes immersion well for easy installation into pipes or vessels without draining the system

Ideal Applications

• High-limit protection on boilers and hydronic heating systems
• Commercial and industrial process temperature control
• HVAC duct and air-handling unit temperature monitoring
• Heat exchanger and fluid system overheat protection

Why Choose the Johnson Controls A19ADB-31?

Built to Johnson Controls’ exacting standards, the A19ADB-31 combines a broad sensing range, robust manual-reset safety action, and a convenient included immersion well into a single, reliable package. The 10-foot capillary gives installers the flexibility to position the control unit away from the sensing point, while the enclosed setpoint adjustment ensures settings remain secure once configured. This thermostat is a trusted solution for professionals who demand dependable high-temperature protection in commercial and industrial environments.