Carrier HH19ZA150 Limit Switch

The Carrier HH19ZA150 Limit Switch is a critical OEM safety control designed to monitor discharge air and heat exchanger temperatures in Carrier, Bryant, and Payne furnaces and air handlers. This auto-reset high limit switch is engineered with a pre-set trip point that opens at 150°F to interrupt the burner circuit or blower motor, preventing hazardous overheating. Once the internal temperature closes at 110°F during the cooling cycle, the switch automatically resets to restore standard operation. Featuring a durable disc-style sensor and a forked brass mounting tab, this component ensures a secure fit within the tight tolerances of the heat exchanger or plenum assembly. As a genuine HH19ZA150 replacement part, it maintains the factory-specified safety parameters required for model 52SEC312-301AA and other compatible residential heating units. Utilizing original equipment ensures precise thermal protection and long-term reliability in demanding HVACR environments.

• Factory Calibrated Precision: Fixed 150°F open and 110°F close settings provide accurate overheat protection without the need for field adjustments.
• Automatic Reset Functionality: Eliminates manual intervention by restoring the electrical circuit once temperatures return to safe operating levels.
• OEM Compatibility: Specifically designed to replace obsolete or failing HH19ZA450, P331-2145, and 302334-410 part numbers.
• Rugged Construction: Built with industrial-grade materials to withstand high-cycle thermal stress and harsh furnace environments.

How do I know if my HH19ZA150 limit switch is bad?
If your furnace is short-cycling or the blower runs continuously while the burners fail to ignite, the limit switch may be stuck in the open position. Use a multimeter to check for electrical continuity during a call for heat; a failed switch will show an open circuit even when cool.

Is the Carrier HH19ZA150 compatible with other brands?
While primarily used in Carrier-made equipment, it is also the standard high limit safety for various Bryant and Payne air handlers and furnaces. Always cross-reference your specific model number to ensure the 150 degree open thermal profile is correct for your application.

Where is this switch typically mounted?
This disc limit switch is usually found mounted on the furnace vestibule panel or directly on the heater's casing near the heat exchanger to accurately sense internal air temperature.

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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.