Analysis of the seven major causes of air-conditioning freezing, the idea should be correct, and the troubleshooting should be accurate and fast~
Small split air conditioners often have icing in the indoor unit evaporator in summer. Why does it freeze and how to eliminate it? Here are the following:
1. Insufficient refrigerant, the split air conditioner may leak or leak due to installation or long use time. After the refrigerant in the refrigeration system is reduced, the evaporation pressure is too low, causing the evaporator to freeze. The location of the icing is generally in the front part of the evaporator. The troubleshooting method is to deal with the leaking part first, add enough refrigerant, the fault will be eliminated.
2. Compressor efficiency is low, compressor failure has been used for a long time, compressor compression efficiency is reduced, or compressor air distribution system is damaged, resulting in low pressure and freezing. The icing position is also in the front part of the evaporator, the former can be supplemented with some refrigerant, the fault can be eliminated. If the fault persists, the compressor must be replaced.
3. There is too much refrigerant, and some air conditioners are refilled with refrigerant due to displacement, leakage and other reasons. The maintenance personnel added more refrigerant improperly, causing too much refrigerant to flow to the evaporator and partially evaporate and freeze. This type of ice is mostly formed around the back part of the evaporator and the compressor return pipe. Drain the excess refrigerant and the fault will be eliminated.
4. The heat exchanger is dirty and the evaporator is dirty. After the air conditioner is used for a period of time, dust in the air or microorganisms produced by the evaporator will accumulate on the evaporator, obstructing air circulation, resulting in reduced heat exchange and low evaporator temperature While freezing. The freezing position is behind the evaporator. After the ice melts, rinse the evaporator with water and brush along the fins with a soft brush. Be careful not to wet the electrical parts. After cleaning, the fault will be eliminated.
5. Poor temperature probe or improper installation position of temperature probe, temperature control failure, mechanical thermostat temperature sensor bulb gas pressure changes with temperature changes, driving the thermostat contact action. Due to contact adhesion, insufficient spring force, etc., the contacts are normally closed, and the air conditioner is continuously turned on, causing icing. Replace the thermostat, troubleshooting.
There are also special circumstances, the thermostat is not damaged and the air conditioner stops for a short time or does not stop. Since the temperature sensor is suspended in the middle of the evaporator with a U-shaped plastic shelf, it is about 2mm away from the fin. It is estimated that this design of the manufacturer is intended to delay the temperature of the temperature sensor package of the thermostat and prevent the air conditioner from frequently starting in a short time (within 3 minutes). In the summer season, the indoor temperature is high, coupled with the limitation of the air conditioner itself, it is difficult for the thermostat to reach the temperature control breakpoint, the air conditioner has a short shutdown time, or even starts continuously, resulting in freezing. This type of ice is mostly formed in the lower part of the evaporator. In this case, move the temperature sensing bulb to the lower end of the evaporator and fix it closely to the evaporator fins, and the fault will be eliminated.
6. The air volume of the internal unit is small, and the air volume is small. After the air conditioner is used for a period of time, some fan blades have a lot of dirt, which affects the air supply and causes the evaporator to freeze. Clear the dirt, troubleshooting.
Some fans also slow down due to mechanical and electrical failures, and the air volume is small, causing the evaporator to freeze. The mechanical reasons are mostly the wear of bearings and bushes, the increase of resistance and the slower speed. Electrical faults are mostly capacitor charging and discharging failures or short circuits between turns of the fan, resulting in slow speed, or even burning of the fan windings and the motor not rotating. This kind of icing phenomenon must be repaired or replaced according to the specific situation.
7. The temperature setting is too low, some users set the air conditioner temperature too low, the cooling capacity of the air conditioner cannot keep up, the room temperature drops below the set temperature and the machine is turned on for a long time, or the shutdown time is very short, which will also cause the evaporator to fail. ice. In some rooms, the temperature drops very low, which can also cause the evaporator to become too cold and freeze. This type of ice mostly begins to freeze in the lower part of the evaporator. As long as the temperature is set higher, the fault can be eliminated.
