U4 - daikin Air Conditioner

中文

含义

U4 为室内外机通讯故障。内外机之间的信号传输中断。

常见原因

1. 连接线断裂或松动
2. 通讯线极性接反
3. 室外机断电
4. 控制板通讯电路损坏
5. 强电磁干扰

自助排查

1. 检查内外机连接线
2. 确认通讯线接线端子
3. 断电重启
4. 联系大金售后

English

Meaning

Communication fault between indoor and outdoor units.

Common Causes

1. Connection wire broken or loose
2. Polarity reversed
3. Outdoor unit powered off
4. Control board comm circuit damaged
5. Strong EMI

Self-Check Steps

1. Check indoor/outdoor wiring
2. Verify comm terminal connections
3. Power cycle
4. Contact Daikin service