I've got a deep (300 ft or so, if I remember right) well with a submersible pump. I had this house built 22 years ago, and never had a problem with it....until a few days ago.
Now, I have low pressure at the pressure tank in the house...about 20 psi on the gauge. I shut off the pump this morning while I was gone and checked the pressure when I got back this evening and it showed about 10 psi. When I turned the pump back on, the pressure took about 5 minutes to build from 10 to 20, where it stopped going up, and I didn't hear the pressure switch cut out, so I guess it's running continuously now. I was thinking that this test might rule out a leak somewhere that was preventing it from reaching the usual 40 psi pressure.
Any direction on what the most likely failure is here? Tired weak pump? Leak in pipe from pump to house? I really don't know much about wells or pumps and no clue as to what model pump is down there, but it's worked perfectly for a long time.
I'm trying to get an idea whether I should call the well company or a plumber.
Was I just lucky that it lasted this long? What is typical life for a pump in this application?