this is an automatic reset snap disc

featuring a regulator spring

reducing callbacks due to carbon fouling or ceramic cracking

How do I test the coil on the 42-18287-12

Resideo TH114-A-120S Thermostat 320074-702 this is an automatic resetThe Resideo TH114 A 120S is a high performance non programmable line voltage thermostat engineered for precise control of 120V electric heating systems. Designed for heavy duty applications, this unit features SPST switching and a 15 amp resistive load capacity, making it an ideal solution for baseboard heaters, convector units, and fan forced heaters. Utilizing advanced TRIAC switching technology, the TH114 A 120S eliminates the clicking noise