Plumbing Questions? Ask a Plumber and Get Answers ASAP.
Welcome to Just Answer, my name is ***** ***** I will do my best to help you with your issue. If my initial response doesn’t answer your question then let me know and we can continue our conversation.
If the water won't shut off and the water is going over the top of the overflow pipe then you'll probably need to replace the fill valve. A Fluidmaster fill valve is your best bet. They are inexpensive (~$15) are widely available and come with good instructions. You could try adjusting the water level but some models are not adjustable. Here is a link to the manual for this toilet. Fill valve adjustment is on page 6