A refrigerator is a refrigeration device that maintains a constant low temperature, and it is also a civilian product that keeps food or other items in a constant low-temperature state. Inside the box are a compressor, a cabinet or a box for the ice maker to freeze, and a storage box with a refrigerating device. The volume of household refrigerators is usually 20 to 500 liters.​

　　In 1910, the world's first domestic refrigerator with compression refrigeration was introduced in the United States. In 1925, the Swedish Lido Company developed a household absorption refrigerator. In 1927, General Electric Company of the United States developed a fully enclosed refrigerator.

　　In 1930, air-cooled continuous diffusion absorption refrigerators with different heating methods were put on the market. In 1931, a new refrigerant, Freon 12, was successfully developed. In the second half of the 1950s, the production of household thermoelectric refrigerators began, and China began to produce refrigerators in the 1950s.​​

　　The excessive refrigerant in the refrigeration system of the refrigerator will cause the noise of the compressor to become louder, and the power consumption of the refrigerator will increase, which will cause the compressor to burn out. The total capacity of the refrigeration system of the refrigerator is very small, so when filling the refrigerator with refrigerant, it must be weighed with an electronic scale with appropriate accuracy.​

　　If the refrigerator wants to cool, it needs to add refrigerant. If too much refrigerant is added, what will happen to the refrigerator? Adding too much refrigerant will cause the condensing pressure to rise. The operating current is large, the operating temperature of the compressor is high, and the compressor is easily damaged. Add fluoride to freeze all the evaporators in the box.​

　　If too much refrigerant is added to the refrigerator, the noise of the compressor will be particularly loud, and it will consume more power, and even burn out the compressor. The damage is also relatively large, and fluorine must be added accurately, and just right; at the same time, the phenomenon of fluorine leakage must be excluded.​

　　Other faults of the refrigerator: loud noise, uneven bottom corner, compressor noise, freezing in the refrigerator, large vibration, fan noise, solenoid valve noise, display failure, no cooling, too low temperature, poor cooling effect, irregular alarm, No electricity, refrigerator leakage, ice sink, the temperature can not be adjusted, no shutdown, can't start, long boot time, lax door closing, bad door seal.