中文
含义
洗衣机在最大进水时间（通常为 10 分钟）内未能达到目标水位，控制系统判定进水超时。此故障表明进水阀、压力开关或供水系统中某一环节未能正常完成注水流程。
常见原因
- 进水阀滤网堵塞 — 进水阀入口处的滤网因水质杂质或铁锈堆积而堵塞，导致进水流速过低甚至完全阻断。
- 进水阀线圈故障 — 进水阀电磁线圈开路或短路，阀门无法开启；可用万用表测量线圈电阻值（正常范围通常为 500 Ω – 2000 Ω）。
- 供水阀门未开启 — 热水或冷水龙头处于关闭状态，或手柄未完全打开。
- 进水软管弯折或压扁 — 软管被推入狭窄空间导致弯折（kink），或底部被重物压住，水流受阻。
- 供水水压过低 — 市政供水压力不足（低于 20 psi / 140 kPa），阀门在额定时间内无法注满。
- 水位压力开关故障 — 压力开关软管脱落、漏气或开关本身卡住，无法向主控板发送达到水位的信号。
- 主控板检测电路故障 — 进水阀驱动电路异常或压力开关信号回路不良（较为少见）。
自助排查
- 确认冷水和热水龙头均已完全打开，检查进水量是否正常。
- 拔下电源插头，关闭水龙头，拆下进水软管。取出进水阀入口处的滤网，用牙刷或清水彻底清洁后装回。
- 检查进水软管是否有弯折、压扁或漏水迹象，必要时更换软管。
- 启动任意进水程序，听进水阀是否有明显的”嗡嗡”电磁声。如听不到任何声响，进水阀线圈可能已损坏。
- 断开电源，用万用表测量进水阀线圈两端电阻。若测得开路（无穷大）或短路（接近 0 Ω），需更换进水阀。
- 检查水位压力开关软管是否脱落或破损；轻轻吹气检查开关是否正常触发。
- 如以上检查均正常，请联系专业维修人员进一步检测主控板和线路。
English
Meaning
The control board has detected that the washer failed to reach the target water level within the maximum fill time (typically 10 minutes). This indicates a water supply fault where insufficient water or no water enters the tub, causing the machine to abort the fill cycle and display the F28 error.
Common Causes
- Clogged Inlet Valve Screens — Debris, sand, or mineral buildup trapped on the small mesh screens inside the water inlet valve ports restrict water flow into the machine.
- Faulty Inlet Valve Coil — The solenoid coil that opens the inlet valve may be open-circuited or shorted. Normal coil resistance is typically between 500 Ω and 2000 Ω depending on the model. An open coil will not energize, leaving the valve closed.
- Water Supply Valves Closed — One or both household water shutoff valves (hot/cold) are turned off or not opened fully, preventing water from reaching the washer.
- Kinked or Pinched Fill Hoses — The inlet hoses are bent sharply (kinked) or crushed behind the washer, severely restricting flow.
- Low Water Pressure — Incoming water pressure below 20 psi (140 kPa) may not deliver enough volume to fill the tub within the allowed time window.
- Faulty Pressure Switch — The pressure switch or its sensing hose is damaged, disconnected, or leaking. The switch fails to signal the control board that the correct water level has been reached, even though water has filled past the target.
- Control Board Failure — In rare cases, the triac driving the inlet valve or the pressure switch detection circuitry on the main control board has failed.
Self-Check Steps
- Verify that both hot and cold water supply valves behind the washer are fully open. Check that water flows from each hose when disconnected into a bucket.
- Unplug the washer, turn off the water supply, and disconnect the fill hoses from the back of the machine. Remove and inspect the small mesh screens inside each inlet valve port. Clean any debris with a toothbrush and rinse thoroughly before reinstalling.
- Inspect the entire length of each fill hose for kinks, pinches, or bulges. Replace hoses that show signs of wear or obstruction.
- Reconnect the hoses, plug the washer back in, and start a fill cycle. Listen for a distinct humming or clicking sound from the inlet valves. No sound suggests the solenoid coil is not being energized or has failed.
- With the washer unplugged, use a multimeter to measure the resistance across the terminals of each inlet valve coil. If the reading shows an open circuit (OL / infinite) or a short circuit (near 0 Ω), the valve assembly must be replaced.
- Check that the pressure switch sensing hose (typically a clear plastic tube running from the bottom of the outer tub to the switch) is securely attached at both ends and free of cracks or water ingress.
- If all above checks pass and the error persists, the control board or wiring harness may require inspection by a qualified technician.