Johnson Controls A19ABC-42 Utility Thermostat

The Johnson Controls A19ABC-42 is a heavy-duty immersion control utility thermostat engineered for precise temperature management in hydronic heating systems and industrial boiler applications. This SPDT temperature control operates across common line voltages including 120/208/240 Vac, making it a versatile choice for field replacements. It features a broad 100 to 240 degree temperature range with a sensing element consisting of a liquid-filled immersion bulb that delivers rapid response to thermal changes. For granular system tuning, the 6 to 24 degree adjustable differential allows technicians to minimize short-cycling and optimize equipment longevity. The unit is designed for ease of installation, featuring a knob adjustment for setpoint changes and an automatic reset mechanism. This model includes a 1/2 inch NPT well assembly, ensuring the bulb is protected and easily removable without needing to dry-tap or drain the system.

• Universal SPDT switching allows for both heating and cooling or high-limit cutout applications.
• Direct immersion bulb with included well provides superior heat transfer and accurate sensing.
• Adjustable differential (6?F to 24?F) gives contractors control over cycle rates and system efficiency.
• Rugged NEMA 1 enclosure protects internal snap-action contacts from dust and debris.
• Wide voltage compatibility simplifies inventory by covering most standard commercial power requirements.

Can the A19ABC-42 be used as a high-limit safety?
Yes, the SPDT contact action allows it to be wired for open-on-rise applications, though it features an automatic reset rather than a manual lockout.

What is the maximum bulb temperature for this model?
This utility thermostat is rated for a maximum bulb temperature of 290?F (143?C), providing an ample safety margin for high-temperature water systems.

Is the immersion well included with the thermostat?
Yes, this specific configuration includes the copper bulb well with a 1/2 inch NPT brass connector for immediate installation into boiler tappings.

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.