Carrier HH18HV125 Limit Switch

When you are troubleshooting a furnace that is tripping on high limit, you need a reliable, exact-match replacement like the Carrier HH18HV125 Limit Switch. This genuine OEM furnace limit switch is a 95-125F auto limit switch designed as a primary safety control for your HVAC system. It features a Single Pole Double Throw (SPDT) configuration and is rated for 5 FLA at 240 VAC. The switch is engineered to open the circuit on temperature rise at 125°F and includes an automatic reset function that closes the circuit once the temperature drops back to 90°F. For contractors and service techs, this manual reset limit switch alternative ensures that the heat exchanger does not exceed safe operating parameters, preventing equipment damage and ensuring consistent performance in Carrier, Bryant, and Payne units.

• Precision Thermal Sensing: Maintains strict safety limits with a 125°F trip point to prevent heat exchanger cracking.
• Auto-Reset Functionality: Transitions back to a closed state at 90°F without requiring manual intervention, reducing unnecessary service calls for temporary over-temp events.
• OEM Compatibility: Designed specifically for Carrier-family equipment, ensuring the correct footprint and electrical terminal alignment.
• Durable Construction: Built to withstand the high-cycle demands of residential and light commercial furnace environments.

• What does it mean if my furnace is throwing a "Limit Switch Open" code? This usually indicates restricted airflow, often caused by a dirty filter or a failing blower motor, which has tripped the safety. If the airflow is clear and the switch remains open, the component may need replacement.
• Can I use an HH18HV125 as a universal replacement? While it fits many models, you must verify the temperature set points and mounting style. Using a switch with the wrong temperature rating can lead to safety hazards or frequent cycling.
• Is this switch SPST or SPDT? This specific model is an SPDT (Single Pole Double Throw) switch, providing versatility in control circuit wiring for both heating and cooling interlocks.

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.