Carrier HH12ZB250 Limit Switch

The Carrier HH12ZB250 Limit Switch is a critical safety component designed for high-temperature monitoring in HVAC furnace plenums and heat exchanger compartments. This OEM replacement part is engineered to open the electrical circuit when temperatures reach 250°F and automatically reset once the system cools to approximately 210°F. Featuring a 3-inch insertion length and a panel-mount configuration, the HH12ZB250 limit switch ensures a precise fit for a broad range of Carrier, Bryant, and Payne equipment, including 58DFA and 58GP models. As an auto-reset high limit switch, it provides reliable protection against overheating without requiring manual intervention after a thermal event. This SPST, normally closed switch replaces multiple legacy part numbers, including HH12ZA251 and P331-2208, maintaining the original equipment’s safety ratings and operational specifications. For technicians, this furnace high limit switch is the standard choice for restoring system integrity and preventing heat-related damage to the heat exchanger.

• Precise Thermal Protection: Factory-calibrated to open at 250°F, ensuring the furnace safety circuit triggers before equipment damage occurs.
• Automatic Reset Functionality: Eliminates nuisance service calls by automatically closing the circuit at 210°F once safe operating temperatures are restored.
• Drop-In OEM Compatibility: Designed with a standard 3-inch probe for direct installation in Carrier, Bryant, and Payne residential furnaces.
• Verified Technical Specifications: Rated for 240V applications with a robust SPST configuration to match original factory performance.
• Cross-Reference Reliability: Serves as a direct technical replacement for obsolete parts like the HH12ZA251 and P331-2208.

What causes the HH12ZB250 limit switch to trip frequently?
Repeated tripping usually indicates restricted airflow, often caused by a dirty air filter, blocked return vents, or a failing blower motor. If the switch remains open despite normal airflow, the internal bi-metal disc may be fatigued, requiring a replacement Carrier HH12ZB250.

Can I use this switch in a furnace requiring a different temperature range?
No. Furnace limit switches are safety-critical components calibrated to the specific thermal limits of the heat exchanger. Always match the "Open" temperature (250°F) and "Close" temperature (210°F) exactly as specified by the manufacturer.

What is the purpose of the 3-inch insertion length?
The 3-inch probe carries the thermal sensor into the optimal position within the plenum or heat exchanger air stream to sense the most accurate temperature data for the safety circuit.

This item is not eligible for free shipping.

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.