If your standalone refrigerator is still freezing everything inside even after replacing the thermostat, there are several other potential causes to consider:
Temperature Control Setting: Double-check the temperature control setting on your refrigerator. If the control is set to a very cold temperature, it can cause the refrigerator to continue cooling excessively, leading to items freezing inside. Adjust the temperature setting to a warmer level and observe if the issue persists.
Thermistor Malfunction: Some modern refrigerators use a thermistor to monitor the temperature inside the unit. If the thermistor is faulty or incorrectly installed, it may not accurately sense the temperature, leading to improper cooling. A malfunctioning thermistor can cause the compressor to run continuously, resulting in items freezing.
Airflow Obstruction: Check for any obstructions in the refrigerator's airflow system. If the air vents or fan are blocked by food items or debris, cold air may not circulate properly, leading to uneven cooling and freezing of items in certain areas.
Defrost Timer or Defrost System Issues: A malfunctioning defrost system can cause excessive frost buildup on the evaporator coils. When the defrost system fails to remove this frost, it can restrict airflow and cause the refrigerator to cool excessively.
Damaged Door Gasket: A damaged or worn-out door gasket can allow cold air to escape from the refrigerator, leading to increased cooling efforts and items freezing inside. Check the door gasket for any tears, cracks, or gaps and replace it if necessary.
Compressor or Control Board Problems: Issues with the compressor or the refrigerator's control board can result in irregular cooling cycles, leading to freezing in the refrigerator section.
Improper Placement: If the refrigerator is placed in an area with extremely low ambient temperatures (e.g., a garage during winter), it may lead to overcooling and freezing of items inside.
If you've ruled out the above possibilities, it's best to consult a professional refrigerator technician. They have the expertise and tools to diagnose and address more complex issues that may be causing your refrigerator to freeze items despite replacing the thermostat.