International Comfort Products 1184421 Auto Limit Switch 160-180°F

This is an automatic reset limit switch used on residential natural gas furnaces and air handlers, part number 1184421. It is a single-pole, single-throw, normally closed (SPST-NC) switch that opens at 180°F and closes at 160°F, providing high-limit protection against overheating. Manufactured by Therm-O-Disc as the Series 60T, it includes a gasket for mounting. Typical failure symptoms addressed by replacement include furnace overheating, unexpected shutdown, failure to reach set temperature, and nuisance high-limit trips. This switch is an OEM replacement suitable for equipment from ICP, Heil, Tempstar, Arcoaire, Comfortmaker, Snyder General, KeepRite, and Day & Night. Installation should be performed by a qualified HVAC technician, matching existing mounting configuration and gasket placement to ensure proper sensing contact with the furnace heat exchanger or plenum.