Error Codes for Siemens VM6125XL Drum Washing Machine:
F01: The washing machine door is not closed properly. Check if clothes are caught in the door gap, and close the door of the washing machine.
F02: The water tap is not turned on, the inlet hose is tangled or pressed by foreign objects, the inlet water filter is clogged, or the water pressure is too low.
F04: The drainage pump is blocked, or the drain pipe is clogged. Clean the drainage pump and the drain pipe.
Source: Beijing Siemens Washing Machine After-sales Service Phone http://blog.sina.com.cn/ximenzixiyji.