Haier air conditioner: abnormal display of indicator light, unable to heat.
Source: Beijing Haier Air Conditioner Repair Center http://blog.163.com/haierktiao_2012/, Beijing Haier Air Conditioner Repair.
Repair method: Fault resolved after handling the connector.
Fault phenomenon: The orange indicator light of the indoor unit timer is on, and the green operation indicator light flashes with a frequency of once every 8 seconds. The entire system can cool normally but cannot heat.
Analysis and actual measurement: Preliminary judgment indicates a fault in the temperature sensor. The indoor unit has three sensors: the吸入air temperature sensor TH1, the evaporator temperature sensor TH2, and the discharge air temperature sensor TH3, which are used respectively for room temperature adjustment, indoor air supply control during heating, overload control during heating, and anti-frost control during cooling. Based on the flashing frequency of the green operating indicator light, it was determined that the evaporator temperature sensor TH2 was malfunctioning. Upon inspection, it was found that its connector had poor contact.