What is the problem that both copper tubes of air conditioner are cold?

How is the copper tube hot and the copper tube cold when the air conditioner is heating?

When heating, one pipe is hot and the other pipe is hot, not cold.

Large indoor air volume: the heat exchange inside the machine is too strong and the pipes are too thin. The temperature should be around 30 degrees at this time.

Reduced refrigerant: resulting in reduced outdoor heat absorption. Thick pipes are hot, but not hot. The tubule is cold. Low system pressure: it may be that the throttling device is not good.

Why do some air conditioners work when a copper tube is hot and a copper tube is cold, and some air conditioners work when both copper tubes are cold?

One copper tube is hot and the other is cold when the air conditioner is heating. Both copper tubes are cold when the air conditioner is cooling!

When the air conditioner is turned on for heating in winter, is it normal for the two copper pipes of the external machine to be cold? How normal should it be?

Don't worry about the temperature of the copper tube, look at the temperature of the indoor unit, as long as the indoor unit is hot air, it will be normal.

What is the problem that both copper tubes of air conditioner are cold?

This is normal for household air conditioners that tear down walls or cabinets, otherwise it is abnormal. The refrigerant is discharged through the compressor, and the high-temperature and high-pressure gas enters the condenser for cooling and condensation, which is called outdoor temperature. The high-pressure liquid becomes low-pressure and low-temperature liquid through throttling electronic expansion valve or capillary throttle valve, enters the connecting pipe of the inner and outer pipes of the air conditioner through pipelines, evaporates through the evaporator, and then evaporates into low-temperature and low-pressure gas through the heat of the evaporator, and the low-temperature and low-pressure gas returns to the compressor again through the thick pipes in the inner and outer connecting pipes of the air conditioner to complete a refrigeration cycle. Therefore, in general, the two connecting copper pipes between the indoor unit and the outdoor unit of the air conditioner are cold. Of course, this is another air conditioner with a built-in damper. Refrigeration operation is hot in thin tubes and cold in thick tubes.