Water level detection system for a washing machine appliance and methods for operating the same

A washing machine appliance comprising:

• a sump for collecting wash fluid;
• a supply valve for providing a flow of the wash fluid into the sump during a fill cycle;
• a water level detection system comprising an air chamber fluidly coupled to the sump and a pressure sensor;
• and
• a controller operably coupled to the supply valve and the water level detection system, the controller being configured for:
• (a) determining that the pressure sensor of the water level detection system is partially blocked;
• (b) obtaining a target fill volume;
• (c) determining a remaining fill volume for the wash fluid to reach the target fill volume;
• (d) opening the supply valve to provide a fraction of the remaining fill volume into the sump and then closing the supply valve;
• (e) determining that a sump pressure measured by the water level detection system has stabilized;
• and
• (f) repeating steps (c)-(e) until a stopping criterion occurs.