Carrier HH18HV170 Limit Switch

The Carrier HH18HV170 Limit Switch is a critical safety component designed for precise thermal regulation in Carrier, Bryant, and Payne heating systems. This OEM replacement part features a normally closed (NC) configuration, engineered to open on temperature rise at 170°F and automatically reset when the system cools to 140°F. Built with a snap-action disc mechanism, the high limit switch ensures a rapid and reliable electrical break to prevent heat exchanger damage and hazardous operating conditions. With electrical ratings of 10A at 120VAC and 5A at 240VAC, this 142-170 degree automatic limit provides the rugged durability needed for demanding residential and industrial HVAC environments. Its SPST design and screw terminal connections allow for straightforward integration into existing control circuits, ensuring your equipment maintains peak performance within manufacturer-specified operating parameters. This genuine furnace limit switch replaces multiple legacy part numbers including 63215D1, HH12HB170, and P3312180, consolidating various technical requirements into one dependable solution.

• Precise Thermal Protection: Engineered with a 140°F cut-in and 170°F cut-out range to prevent overheating.
• Automatic Reset Functionality: Eliminates manual intervention by restoring circuit continuity once safe temperatures are reached.
• Direct OEM Compatibility: Ensures exact fit and performance for Carrier, Bryant, and Payne equipment models.
• High-Duty Electrical Ratings: Supports 120V and 240V configurations for versatile application in various control boards.
• Snap-Action Reliability: Features a high-quality disc type mechanism for fast response and long-term cycle life.

• What does the "Automatic" reset feature do? This switch will automatically close the circuit once the plenum temperature drops back down to the 140°F reset point, allowing the unit to resume normal operation without manual resetting.
• How do I verify if this switch is failing? If your furnace is short-cycling or the blower continues to run while the burners stay off, use a multimeter to check for continuity across the switch terminals during a call for heat.
• Can this replace other 170-degree limit switches? While it replaces several ICP and Carrier part numbers like 57480C03 and 46W34932C, always verify the specific differential and mounting footprint before installation.

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.