There are many reasons that can cause the water level in the fully automatic washer to rise. These can be broadly categorized into two types: high water levels triggered before water is supplied, and high water levels occurring after water supply has begun.

1. Cause of high water level triggered before water intake in the fully automatic washer-extractor:

a. The hotel uses both imported and domestically manufactured washing machines. Whether imported or domestic, these machines come in a wide variety of brands and specifications, each with its own unique characteristics. Moreover, different brands exhibit varying degrees of precision in water-level control, as there is no universally standardized approach. This results in inconsistencies, with some machines offering higher or lower levels of water control accuracy.

b. When setting the washing machine program, the main wash water level can be adjusted to either high or low. For example, a hotel laundry facility is equipped with two domestically produced, fully automatic 100 kg-capacity washer-extractors from different brands. Both machines are used to wash the same linens, yet their main wash water levels are set differently—one at 40 cm and the other at 30 cm, resulting in a significant disparity between the two machines' settings.

c. Manual control of water supply, inadequate low-water-level standards, improper management practices—such as the absence of clear water-level guidelines—or a lack of accountability leading to arbitrary water-level adjustments. In some cases, the water level during the main wash cycle even reaches the height of the high-water mark.

d. The water level switch malfunctioned, causing control failure and raising the water level threshold for control, which resulted in an increased water injection level.

2. Causes of high water level triggered after the fully automatic washer is filled with water:

a. Low steam pressure significantly increases the water volume in the washing machine, causing the water level to rise. Under normal steam pressure conditions (4–6 kg), the typical heating time should be within 10 minutes. However, it is reported that many laundries experience unstable steam pressure—sometimes high, sometimes low. In cases of low pressure, it can even drop below 2 kg. At such reduced pressure levels, the heating process takes considerably longer, often requiring more than an hour. This prolonged heating leads to excessive condensation of steam into the washing machine, further elevating the water level.

b. Typically, operators begin loading materials only after the water filling process is complete. At this point, the washing machine's water-level control program has already ended and no longer exerts any control over water level changes. As a result, all the water used for material rinsing flows directly into the washing tub, causing the water level to rise.

c. The inlet valve is leaking, causing continuous water inflow into the washing tub throughout the entire wash cycle, which raises the water level.