What would the problem be if i get Water Level Sensor error(E1)?

What would the problem be if  i get Water Level Sensor error (E1) ?

There are a lot things that might contribute to this, but these are the main reasons :

• The part of the hose where the water level sensor is located is damaged (punctured)
• The hose is cloggedwith foreign material
• The hose is folded
• Too much lubricant has been applied to the insertion part of the air hose
• Hose engagement error (disengaged)
• Parr faulty ( Faulty internal soldering)
• The water level sensor terminal is disengaged)
• Main PBA fault.