It indicates a "Close on" (automatic) reset logic where the switch opens at 150°F and closes automatically when the temperature cools

How do I verify if the 24V coil is failing

Industrial Durability: Engineered with premium materials to withstand rapid thermal cycling and high-heat environments for extended service life

Designed to replace legacy part numbers 322023-703

but always cross-reference the specific model number and serial number of the unit to ensure the correct BTU rating and physical dimensions

Carrier HC41FB666 Motor 319848-301 It indicates a "Close on"The Carrier HC41FB666 Motor is a high performance 1 3 HP blower motor designed for professional HVAC applications requiring 208 230V power. Operating at a fixed 1550 RPM, this OEM Carrier replacement motor ensures optimal static pressure performance and consistent airflow within residential and light commercial air handlers and furnaces. Featuring a durable rolled steel frame and thermal overload protection, it is built to handle the rigorous duty