The fifth gear is the coldest. 1 gear has the highest temperature, and the fifth gear has the lowest temperature. The higher the number, the lower the temperature. The gear level of the refrigerator can be adjusted according to the seasonal ambient temperature. In summer, it should be adjusted to a relatively small digital gear to avoid the difficulty of cooling down due to excessive indoor and outdoor temperature difference. In winter, the refrigerator should be adjusted to a relatively large gear. It is most suitable to keep the freezing room at MINUS 18 degrees and the refrigerating room at 4 to 8 degrees. Related knowledge science: 1, the thermostat of refrigerator should be turned on at low level in summer, and at high level in winter. When the ambient temperature is too high in summer, it should be used at the second or third gear, and when the temperature is low in winter, it should be used at the strong gear of four or five degrees. Because the outside temperature is very high in summer, if the freezing room is still blocked, the temperature difference between indoor and outdoor will be too large, and it will be very difficult for the refrigerator to drop 1 degree. Through the insulation layer of the box and the crack of the door, the loss of cold air will be accelerated. After a long time, the life of the compressor will be shortened and the use efficiency of the refrigerator will be affected. 2. When the ambient temperature is relatively low in winter, if the thermostat is still set to the weak position, the temperature difference between inside and outside will be too small, and the compressor will not be easy to start. The refrigerator with single refrigeration system may also have the phenomenon of freezing in the freezing room. Post-processing will be very troublesome.