Carrier HH680351 Switch

The Carrier HH680351 Switch is a high-limit safety component engineered for precision temperature monitoring in residential and light commercial HVAC systems. This OEM limit switch functions as a critical safety cutoff, featuring a factory-set 220-degree open threshold and a 20-degree differential for a consistent 200-degree reset point. Designed specifically for high-heat heat exchanger applications, this SPST furnace limit switch ensures system integrity by interrupting the burner circuit if plenum temperatures exceed safe operating parameters. The HH680351 furnace sensor is built to withstand high-cycling demands and maintains low electrical resistance across terminals to prevent nuisance trips. When replacing a fixed-mount limit control, verify that the insertion depth and temperature rating match the original equipment specifications to maintain the UL listing of the appliance. Its robust construction ensures long-term reliability in high-ambient environments typical of modern high-efficiency gas furnaces and air handlers.

• Precision Thermal Control: Features a calibrated bimetal disc for accurate 220°F interruption and a fixed 20°F differential.
• Direct OEM Replacement: Ensures exact fit and function for specific Carrier, Bryant, and Day & Night units.
• High-Temperature Durability: Integrated ceramic insulation and high-grade metal housing prevent thermal degradation.
• Optimal System Safety: Prevents heat exchanger damage and hazardous operating conditions by detecting airflow restrictions.

Common HVAC Questions

What causes a 220-degree limit switch to trip frequently?
Nuisance tripping is often caused by restricted airflow, such as a clogged MERV-rated air filter, a failing blower motor, or undersized ductwork that prevents heat dissipation.

Can the HH680351 be used in non-Carrier brands?
While this is a Carrier-certified HVAC part, it may be used in other brands if the temperature specs, mounting footprint, and electrical load ratings align exactly with the technical data sheet.

Is the HH680351 a manual or automatic reset switch?
This is an automatic reset limit switch; it will re-engage the circuit once the sensed temperature drops below 200°F (the 20-degree differential below the opening point).

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.