Reason 1.Water level not met in 8 minutes.
Solution 1.Make sure that tap is turned on, and water pressure is normal.
Reason 2.The height of the drain hose is below 80 cm.
Solution 2.Install drain hose within 80-100 cm of height
Reason 3.The drain hose is in water.
Solution 3.Make sure the drain hose is not in water.