Beijing Chigo Air Conditioning After-sales Service Phone Number http://blog.tianya.cn/blogger/blog_main.asp?BlogID=3482552 Case Data Sharing. Fault Phenomenon: During winter heating, the air conditioner still blows cold air. Fault Analysis: This kind of fault mostly occurs in the four-way reversing valve and its drive control circuit. Fault Inspection: (1) Check the four-way reversing solenoid valve, no reversing sound. During reversing, pin 15 of IC1 should be high level, and pin 15 of IC5 should be low level. If the reversing voltage is normal, Beijing Chigo Air Conditioning Repair, focus on checking whether the relay 52X4 is damaged. When the relay is normal, then the four-way reversing solenoid valve should be replaced. (2) After inspection, it was found that the four-way reversing solenoid valve itself was damaged. After replacing with a new four-way reversing solenoid valve, the heating returned to normal, and the fault was eliminated. Chigo ZG388 type air conditioner, still blowing cold air when heating.