Use manual level or deep fill only within the programs that allow it. The reference is the load-to-water ratio in the manual, not how much liquid you can see from the door.
Recognizing the control type
A machine may ask for load size, offer water levels, or calculate the fill automatically. Deep Fill is another possible option, with its own restrictions. Do not treat these controls as if they were the same function.
On models that require manual selection, match the level to the load according to the chart. On automatic models, a small visible amount does not prove there is too little water: look for a real fill failure or just an expectation based on a different design.
Bulky items and product concentration
An approved comforter needs space and proper distribution in addition to the expected water level. Adding water does not make an item allowed if the machine forbids it, nor does it solve a load that is too large. First check the conditions for washing bulky textiles.
Changing the level can change the water-to-detergent ratio. Follow the product and model instructions; do not compensate with improvised scoops. Keep a record of the dosage used to interpret the result.
Avoid manual corrections to an automatic cycle
Do not pour water in with containers to fool the sensing system or alter sensors. If an option appears disabled, check its compatibility with the program. If there is a real supply problem, stop the test and consult the equipment diagnosis.
If you are unsure about the fill, compare the behavior with the selected program before trying to add more water.