Johnson Controls A19ABC-11 Temperature Control

The Johnson Controls A19ABC-11 is a robust mechanical temperature control designed for demanding hot water immersion applications. This SPDT temperature switch features a liquid-filled sensing element that ensures rapid response to temperature fluctuations, making it an ideal operating control for hot water boilers and general-purpose heating systems. The unit operates across a 100 to 240 degree F setpoint range with an adjustable differential of 6 to 24 degrees F, allowing technicians to fine-tune system cycles for optimal efficiency. Engineered for versatility, it supports 24 to 277Vac electrical ratings and provides Open High (R-B) or Opens Low (R-Y) switching logic. The automatic reset functionality ensures consistent performance without manual intervention. This direct replacement for 433 and A19ABC-11C comes standard with a 1/2" NPT well connector and a convertible range adjuster, facilitating seamless integration into existing hydronic piping. Whether you are performing a universal replacement or a new installation, this industrial-grade thermostat offers the precision and repeat accuracy required by professional HVACR contractors.

Key Benefits

• Universal Compatibility: Serves as a direct replacement for Johnson Controls 433 and A19ABC-11C models.
• Fast Thermal Response: The liquid-filled element provides high-speed sensing for precise boiler water temperature management.
• Flexible Adjustment: Features a convertible range adjuster for knob, internal, or external screwdriver slot settings.
• Industrial Durability: Housed in a NEMA 1 enclosure with dust-tight, snap-acting contacts to ensure long-term reliability in mechanical rooms.
• Wide Voltage Range: Rated for 24V to 277V, making it suitable for a variety of commercial and residential control circuits.

Common Questions

• How do I wire the A19ABC-11 for heating vs. cooling? For heating (open high), use terminals Red (Common) and Blue. For cooling or low-limit applications (open low), use terminals Red (Common) and Yellow.
• Can the differential be adjusted while the system is live? While physically possible, it is professional best practice to disconnect power before removing the cover to adjust the 6 to 24 degree F differential lever.
• Does this include the immersion well? Yes, the A19ABC-11 is furnished with a 1/2" NPT well assembly for direct immersion in tanks or piping.

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.