noise when wellpump shuts off Home › Forums › Public Forums › General Plumbing › noise when wellpump shuts off This topic has 1 reply, 2 voices, and was last updated 24 years, 5 months ago by Art_xyz. Viewing 1 reply thread Author Posts 14 Mar 2000 at 4:38 pm #272643 MasterPlumbersKeymaster Our pump and pressure tank are four years old. Just recently, there is a loud double “thunk” and the pipe jumps whenever the pump turns off. There is no loss of water pressure or any other symptoms. What could be doing this? 19 Mar 2000 at 4:25 pm #286063 Art_xyzParticipant The noise is caused by your check valve, it seems that the lower your water level the harder the valve closes. Author Posts Viewing 1 reply thread You must be logged in to reply to this topic. Log In Username: Password: Keep me signed in Log In