Before disassembling the air conditioner, you should first determine its working condition. This creates conditions for recovering the refrigerant and avoids unnecessary trouble and disputes. Connect the power supply, set the air conditioner to cooling mode, and slowly close the liquid valve (thin pipe) of the outdoor unit with a hex wrench so that the refrigerant in the outdoor unit no longer flows into the indoor unit. The refrigerant originally retained in the indoor unit will be drawn back by the compressor into the outdoor unit. After about 60 seconds, the refrigerant can be completely recovered. Then quickly close the gas valve (thick pipe) with a hex wrench, turn off the power supply, and install the valve cap tightly. This prevents system leakage and protects against damage to the threads or foreign objects entering the interface during transportation. Both ends of the removed connecting pipes should be fitted with plastic caps to prevent dirt and humid air from entering. The pipes should not be left for too long, and care should be taken during handling to avoid flattening or breaking.
Accurately control the recovery time; if it's too short, the refrigerant may not be fully recovered; if it's too long, since the liquid valve is already closed, the exhaust resistance of the compressor increases significantly, leading to severe heating. As the refrigerant cools down, the compressor is prone to burning out. To prevent the compressor from sucking in air through the low-pressure valve, the low-pressure valve should be closed quickly during refrigerant recovery. If a vacuum has been created on the low-pressure side, air might enter the system. The recovery time can be controlled using the gauge pressure method (where gauge pressure remains negative and constant) or the time method (about 60 seconds).
After installing the air conditioner, a trial run should be performed to check if additional refrigerant needs to be added. Methods for judgment include the gauge pressure method (the corresponding evaporation pressure for R22 is approximately 0.5 Mpa), the current method (current matches the rated value marked on the label), and the observation method (checking condensation, outlet temperature, and condensate drainage).
For Sanyo air conditioners, attention should be paid to certain issues when moving the unit. Information source: Beijing Sanyo Air Conditioner After-sales Service Phone; Beijing Sanyo Air Conditioner Repair Phone http://blog.tianya.cn/blogger/blog_main.asp?BlogID=3944059.