中文
含义
E2 为增压水泵故障。净水器检测到增压泵运行电流异常、无法正常启动或运行时水压未达到 RO 膜正常工作压力，控制器判定水泵故障并停止制水，防止水泵干转烧毁或 RO 膜因水压不足而无法有效过滤。
常见原因
- 增压泵电机卡死或绕组烧毁，通电后无法转动。
- 供水水压过低或进水电磁阀未正常开启，水泵入口无水导致空转保护触发。
- 增压泵电容损坏或驱动电路故障，电机无法获得正常启动力矩。
- 管路或滤芯严重堵塞，泵出口阻力过大导致过流保护。
- 低压开关故障，在进水正常时仍输出无水信号，控制系统误禁止水泵运行。
自助排查
- 检查自来水进水角阀是否完全打开，确认家中其他水龙头有水（排除停水）。
- 检查净水器进水软管是否有弯折，确保管路通畅。
- 确认前置 PP 棉滤芯是否已严重堵塞（可根据 APP 中的滤芯寿命或水流量明显变小判断），如已到期或堵塞，更换后重试。
- 断电等待 30 秒后重新通电，观察故障是否消除。偶发性保护可能因瞬间水压波动触发。
- 若以上检查均正常但重新通电后仍报 E2，增压泵或其驱动电路可能存在硬件故障，请联系小米售后服务中心安排检修。请勿自行拆机。
English
Meaning
E2 indicates a booster pump malfunction. The purifier detects abnormal pump running current, failure to start, or that the water pressure during operation has not reached the level required for proper RO membrane filtration. The controller shuts down water production to prevent the pump from running dry and burning out, or the RO membrane from being unable to filter effectively due to insufficient pressure.
Common Causes
- Booster pump motor is seized or the windings are burned out — the pump cannot rotate when energized.
- Feed water pressure is too low or the inlet solenoid valve has not opened properly, causing the pump inlet to be dry and triggering dry-run protection.
- Booster pump capacitor failure or drive circuit fault — the motor does not receive sufficient starting torque.
- Piping or filter cartridges are severely clogged, causing excessive pump outlet resistance and triggering overcurrent protection.
- Low-pressure switch is faulty, outputting a no-water signal even when the feed water supply is normal, causing the control system to incorrectly inhibit pump operation.
Self-Check Steps
- Check that the cold water supply angle valve is fully open and confirm that other taps in the home have water (rule out a water outage).
- Inspect the purifier’s inlet hose for kinks and ensure the water path is unobstructed.
- Check whether the PP cotton pre-filter is severely clogged (indicated by expired filter life in the app or noticeably reduced water flow). If expired or clogged, replace the filter and retry.
- Power off, wait 30 seconds, and power back on to see if the fault clears. An occasional protection trip may have been triggered by a momentary water pressure fluctuation.
- If the checks above are all normal but E2 persists after a power cycle, the booster pump or its drive circuit likely has a hardware fault. Contact Xiaomi after-sales service for diagnosis. Do not attempt to disassemble the unit yourself.