A fridge typically runs for about 8 hours a day. However, this can vary depending on the size and model of the fridge. Energy-efficient models may run for less time, while larger or older models may need to run for longer periods of time. If your fridge is running more or less than usual, it could be an indication that there is a problem with the appliance. If you are concerned, it is best to consult a qualified technician for diagnosis and repair.