... , Mechanic Thermostat, Thermocouple, Thermometer, Thermostat Wiring, HVAC, HVAC Thermostat, Air Heater Fan PRINCIPLE OF OPERATION: With temperature rise, the expansion of liquid ... most household appliances (electric kettle, electric heater, oven, rolling-type washing machine, water boiler etc.), refrigeration industry (refrigerator, ice-maker, cold drinks ...