The Carrier HH19ZA195 Limit Switch is a critical safety component designed for precise thermal monitoring within Carrier residential furnaces and HVAC air handlers. This SPST (Single Pole Single Throw) manual reset furnace limit switch operates as a normally closed contact that opens when temperatures reach the 195-degree trip point and allows for manual closure once the system cools to 155 degrees. Engineered for high-limit protection, the HH19ZA195 prevents heat exchanger damage and ensures safe operating parameters during ignition cycles. Contractors rely on this OEM replacement part for its exact thermal cutout calibration, effectively addressing frequent furnace overheating issues caused by restricted airflow or blower motor failure. Its low-profile design and standard mounting flange ensure seamless integration into the existing control circuit, essential for maintaining HVAC safety switch standards and ensuring reliable furnace sequences in Bryant, Day & Night, and Payne equipment.

Key Benefits for Technicians

• Precise Thermal Calibration: Fixed 195°F open and 155°F close settings prevent nuisance tripping while providing robust heat exchanger protection.
• Direct OEM Compatibility: Verified drop-in replacement for existing Carrier and Bryant furnace limit circuits, eliminating the need for field modifications.
• Simplified Troubleshooting: The manual reset feature provides immediate feedback on high-limit events, assisting technicians in diagnosing airflow obstructions.
• Durable Construction: High-grade ceramic and metal components withstand the rigorous temperature fluctuations found in gas furnace heating cycles.

Common Installation and Troubleshooting Questions

What causes a Carrier HH19ZA195 to trip frequently?
Repeated tripping usually indicates restricted airflow, often due to a clogged air filter, blocked return air grilles, or a failing blower motor. Verify static pressure across the heat exchanger before replacing the switch.

Can I use a different temperature-rated limit switch?
No. Using a switch with a different limit switch temperature rating can lead to unsafe operation or damage to the heat exchanger. Always match the OEM specification of 195 degrees for this application.

Is the HH19ZA195 a normally open or normally closed switch?
This is a normally closed (NC) switch that opens the circuit upon reaching 195°F to interrupt power to the gas valve or ignition control board.

Notes

Non Cancelable / Non Returnable

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.