4-Wire Refrigerator Defrost Thermostat (Bi-metal) – Product Description The 4-Wire Bi-metal Defrost Thermostat is a safety and control device used in refrigerators and freezers to regulate defrost cycles and prevent overheating during defrosting. This thermostat opens and closes based on temperature changes, ensuring efficient and safe operation of the defrost heater. The 4-wire configuration allows for flexible installation in various models of domestic and commercial refrigeration units. Applications Domestic refrigerators and freezers Commercial display fridges and coolers Walk-in freezers and cold rooms Beverage and merchandiser coolers Ice machines with defrost function Features Bi-metal disc design – Offers precise temperature sensing and fast response 4-wire configuration – Enables dual-function control or sensor feedback Automatic reset – Opens and closes circuit based on temperature threshold Moisture-resistant body – Suitable for cold and humid environments Overheat protection – Prevents damage to components during defrost cycles Easy installation – Compatible with most standard refrigeration systems Specifications Voltage: 120V / 240V AC Rated Current: Up to 15A Temperature Range: Opens at ~60°F (15.5°C), closes at ~30°F (-1°C) (varies by model) Wire Leads: 4 x insulated copper wires, pre-stripped ends Mounting: Clip or screw type Body Material: Thermoplastic with stainless steel bi-metal disc Safety Compliance: UL/CSA certified (model dependent) Got Questions? Not sure how to wire a 4-lead defrost thermostat correctly? Want to know the right temperature range for your fridge model?
