Drips and sizzling sounds are common during the defrost cycle and shortly after the defrost cycle finishes, as the melted ice continues to drip on the defrost heater until all ice is cleared out of the freezer or refrigerator section. These sounds are normal, and may make noises for an extended period of time depending on the amount of ice accumulation.
The defrost timer clicks as it initializes and finalizes the cycle, and is stuck if it continues to click well after the typical 30-minute defrost period. Unplugging the refrigerator's power cord from the electrical outlet and waiting for the clicking to stop typically resolves the stuck timer. The defrost timer is set to 30 minutes by default, and requires manually unplugging the appliance from its power source to exit out of the stuck cycle.
The defrost pan located near the bottom of the refrigerator's front panel requires cleaning to eliminate water buildup after the defrost cycle. Water buildup can affect the refrigerator's ability to efficiently defrost, and can result in long or stuck defrost cycles. The defrost pan can be pulled out and cleaned, and should be wiped down after each defrost cycle to maintain refrigerator performance.
Preventing defrost timer problems is possible by maintaining the default thermostat setting for your refrigerator and freezer. A higher cooling setting results in colder temperatures, which causes higher amounts of ice buildup and longer defrost times to melt the buildup. The ideal temperature for the freezer and refrigerator is the middle bar on the front of the refrigerator door's control panel.