Whirlpool WP4387499 Bi-Metal Defrost Thermostat for Refrigerator

The Whirlpool WP4387499 is a bi-metal defrost thermostat used in refrigerators to manage the automatic defrost cycle. This cycle helps to limit frost accumulation in the freezer compartment, which can impact efficiency and storage space. The thermostat operates by detecting temperature variations through the interaction of two different metals bonded together. Once the freezer reaches a specific low temperature, the bimetallic strip bends, interrupting the power supply to the compressor. This halts the cooling process, allowing any built-up frost to melt. As the temperature rises to a predetermined level, the strip straightens, restoring power to the compressor and resuming normal cooling functions. This process is integral to maintaining optimal performance and food storage conditions in a Whirlpool refrigerator.