中文
含义
长虹空调检测到化霜温度传感器故障，显示屏显示 F5 错误代码。化霜传感器安装在室外机冷凝器盘管上，用于监测盘管表面温度以判断结霜程度和化霜时机。在冬季制热运行时，室外机盘管会持续结霜，控制系统依靠化霜传感器数据决定是否启动和结束化霜。传感器故障将导致空调无法正常化霜，室外机盘管被厚冰覆盖，严重影响制热效果。
常见原因
- 化霜温度传感器（NTC 热敏电阻）老化损坏、阻值漂移或开路/短路。
- 传感器与室外机主板之间的连接插头因雨淋受潮而腐蚀或接触不良。
- 传感器未正确固定在冷凝器盘管指定位置，掉落或移位导致测温不准。
- 传感器信号线被老鼠等小动物咬断，或绝缘层老化破损导致信号短路。
- 室外机主板化霜检测电路元件损坏。
- 传感器长期在-20°C 至 +60°C 的极端温差和冷凝水环境中工作，加速老化失效。
自助排查
- 断开空调电源，等待 3 分钟后重新通电开机，观察 F5 是否消除。传感器接触不良导致偶发性故障可能在重新上电后暂时恢复。
- 观察空调制热运行时的室外机盘管：如果盘管已经结了厚厚的冰霜但空调仍不启动化霜（或化霜一直不结束），说明化霜传感器数据异常。
- 检查室外机的安装位置——确保室外机不会被雨水或融雪积水浸泡，传感器和接头受潮是常见故障原因。
- 如果条件允许，断电后打开室外机电器盒盖板（仅观察），查看化霜传感器连接线是否有明显松动或腐蚀痕迹。不要触碰电路板。
- 化霜传感器故障需由专业技师使用万用表对比传感器阻值与标准温度-阻值特性表。请联系长虹空调售后服务中心安排上门检修，更换故障传感器。
English
Meaning
The Changhong air conditioner has detected a defrost temperature sensor fault, displaying the F5 error code. The defrost sensor is installed on the outdoor unit condenser coil and monitors the coil surface temperature to determine the degree of frosting and the timing for defrosting. During winter heating operation, the outdoor unit coil continuously accumulates frost. The control system relies on the defrost sensor data to decide when to start and end the defrost cycle. A sensor fault will prevent the AC from defrosting properly, causing the outdoor unit coil to become covered in thick ice and severely degrading heating performance.
Common Causes
- The defrost temperature sensor (NTC thermistor) has aged and failed, drifted in resistance, or has an open/short circuit.
- The connector between the sensor and the outdoor unit main board has corroded due to rain exposure or has poor contact.
- The sensor is not properly secured at the designated position on the condenser coil — it has fallen off or shifted, causing inaccurate temperature measurement.
- The sensor signal wire has been chewed through by rodents or the insulation has aged and cracked, causing signal shorts.
- Components in the defrost detection circuit on the outdoor unit main board are damaged.
- Prolonged operation in extreme temperature swings (-20°C to +60°C) and condensed water environments has accelerated sensor aging and failure.
Self-Check Steps
- Disconnect the AC from power, wait 3 minutes, then reconnect and start. Observe whether F5 clears — intermittent faults from poor sensor contact may temporarily recover after a power reset.
- Observe the outdoor unit coil during heating operation: if the coil is already covered in thick frost but the AC still does not initiate defrosting (or defrosting never ends), it indicates abnormal defrost sensor data.
- Check the outdoor unit installation — ensure the unit is not submerged in rainwater or melting snow. Sensor and connector moisture is a common cause of failure.
- If accessible, with the power disconnected, open the outdoor unit electrical box cover (for observation only) and check whether the defrost sensor wiring shows visible looseness or corrosion. Do not touch the circuit board.
- Defrost sensor faults require a professional technician to compare the sensor resistance with a standard temperature-resistance characteristic table using a multimeter. Contact Changhong AC after-sales service to arrange an on-site inspection and replacement of the faulty sensor.