Carrier HH18HA217 Limit Switch

The Carrier HH18HA217 Limit Switch is a critical safety component designed for precise thermal monitoring in residential and commercial HVAC systems. Engineered as an OEM replacement part, this L240-50F limit switch features a fixed 240°F open temperature and a 50°F manual or auto-reset differential (typically auto-reset in furnace applications), effectively preventing heat exchanger damage due to airflow restrictions or blower failure. This disc limit switch is built with a rugged snap-action mechanism to provide reliable circuit interruption for Carrier, Bryant, and Payne furnaces.

As an essential furnace high limit switch, the HH18HA217 ensures code compliance and system protection by preventing the plenum from exceeding safe operational limits. Its compact footprint and 3/4-inch disc design allow for versatile mounting in various supply air locations. For service technicians, this part is a direct cross-reference for multiple Carrier furnace parts, offering a stable solution for short-cycling issues caused by thermal over-limit conditions. Integrating this genuine Carrier part maintains the original engineering specifications of the heating unit, ensuring long-term operational safety.

• Precise Thermal Cutout: Calibrated for a 240°F opening temperature to protect the heat exchanger and surrounding components from extreme heat.
• Universal Compatibility: Direct OEM replacement for numerous Carrier, Bryant, and Payne gas furnace models and fan coils.
• Durable Snap-Action Design: High-amperage capacity and robust housing engineered for the harsh environment of a furnace supply plenum.
• Safety Compliance: UL and CSA certified components ensure the unit meets rigorous HVAC technology standards.

What are the symptoms of a failing HH18HA217 limit switch?
Common signs include the furnace blower running continuously without heat, the burner shutting off prematurely (short-cycling), or the control board flashing a specific limit circuit error code. Restricted airflow from a dirty filter often causes this switch to trip.

Is the HH18HA217 a manual or automatic reset switch?
The L240-50F is typically an automatic reset disc switch, meaning it will close the circuit and allow the furnace to fire again once the temperature drops below the 50°F reset point.

Can I use this switch in other HVAC brands?
While designed for Carrier Corporation equipment, it can be used in other applications requiring an L240-50F specification, provided the mounting footprint and electrical ratings match.

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.