中文
含义
化霜盘管温度传感器故障或化霜周期超时。E8 表示制热模式下室外机化霜过程出现异常。可能是化霜传感器故障导致系统无法准确判断化霜时机，或化霜周期超出设定最长时间系统仍未完成化霜。
常见原因
- 室外机化霜温度传感器热敏电阻损坏，阻值异常或开路/短路。
- 化霜传感器探头从铜管固定位置脱落，无法准确测量盘管温度。
- 室外环境温度太低或湿度太高，结霜速度快于化霜速度，化霜超时。
- 化霜控制电路故障（继电器触点粘连或驱动三极管损坏）。
- 四通阀在化霜时无法正常切换，压缩机排出的高温气体无法进入室外换热器化霜。
- 系统制冷剂不足，化霜时高温侧热量不够。
自助排查
- 观察室外机结霜情况——若霜层过厚且持续不化，化霜功能确实异常。
- 找到室外机化霜传感器（通常靠近冷凝器底部或化霜温度最低处），检查探头是否固定良好。
- 用万用表测量化霜传感器阻值，常温应有几 kΩ 到十几 kΩ。若为 0Ω 或无穷大则需更换。
- 化霜系统维修涉及制冷剂管路和电路排查，建议联系 TCL 售后上门检修。
English
Meaning
Defrost coil temperature sensor fault or defrost cycle timeout. E8 indicates an abnormality in the outdoor unit defrost process during heating mode. Either the defrost sensor has failed, preventing the system from accurately determining defrost timing, or the maximum defrost cycle duration was exceeded without completing defrost.
Common Causes
- The outdoor unit defrost temperature sensor thermistor is damaged — abnormal resistance or open/short circuit.
- The defrost sensor probe has fallen out of its fixed position on the copper tube and cannot measure coil temperature accurately.
- Outdoor ambient temperature is too low or humidity is too high; frost builds up faster than defrosting can remove it, causing defrost timeout.
- Defrost control circuit fault (relay contact welding or drive transistor failure).
- The 4-way valve cannot switch properly during defrosting; hot gas from the compressor cannot enter the outdoor heat exchanger to melt frost.
- Insufficient system refrigerant charge; inadequate heat available on the high-temperature side during defrost.
Self-Check Steps
- Observe the outdoor unit frosting — if frost is excessively thick and does not melt, the defrost function is indeed abnormal.
- Locate the outdoor defrost sensor (usually near the lower part of the condenser or the coldest defrost point) and check that the probe is securely fixed.
- Use a multimeter to measure the defrost sensor resistance; at room temperature it should read several kΩ to tens of kΩ. Replace if 0Ω or infinite.
- Defrost system repairs involve refrigerant line and circuit diagnostics. Contact TCL after-sales for on-site service.