242044113 Refrigerator Defrost Heater cycle is initiated based on a timer or through an adaptive control system. Over time, as the refrigerator operates, frost and ice accumulate on the evaporator coils, reducing their efficiency. When the defrost cycle starts, a signal is sent to the defrost heater, which is typically located along the evaporator coils. The heater is made of a conductive material that generates heat when an electrical current passes through it. Once activated, the defrost heater starts to heat up. The heat generated by the defrost heater warms the surface of the evaporator coils, causing the accumulated frost and ice to melt. As the ice melts, it turns into water and drips down into a defrost drain or pan, where it will eventually evaporate. This process clears the frost buildup on the coils and ensures they can operate efficiently to cool the refrigerator.