The normal function of a fridge/freezer door is to seal the refrigerated or frozen compartment to maintain the desired temperature inside. When the door is closed properly, it creates an airtight seal to prevent warm air from entering the fridge or freezer and cold air from escaping.
When the fridge/freezer is turned off (not defrosting), the door should remain fully closed to maintain the internal temperature. Keeping the door closed helps preserve the cold environment inside and ensures that the contents stay fresh or frozen for as long as possible. If the door is left even slightly open, it can lead to temperature fluctuations inside the appliance, potentially causing the food to spoil more quickly or thawing in the freezer.
In some cases, leaving the door slightly open intentionally might be done for short periods, for example, to allow air circulation and prevent odors if the fridge/freezer is being left unused for an extended time. However, in general, it is best to keep the door closed at all times when the appliance is not in use to maintain proper cooling or freezing conditions and conserve energy.