Hi there my hotpoint washing machinewma 54 fills up without the machine being on

Hello. your fill valve is faulty and needs to be replaced.

here is how the fill valve is supposed to work:
The fill valve--which is about the size of a coffee cup--is sometimes also called a "water inlet valve." It controls the entry of hot and cold water into the machine. The valve has three major components:

• A hot-water solenoid
  
  
• A cold-water solenoid
  
  
• A mixing valve body
  
  

• The hot water from the house
  
  
• The cold water from the house
  
  
• The water directed into the washing machine's inner tub (either hot or cold, or both) to fill it with water