We currently have an unknown (in terms of GPM) 3/4HP Franklin well pump, at an unknown depth (though our neighbor's well is at roughly 100'). Since we moved in, when the well pump is running, there has been a low, barely audible humming that can heard throughout the house. About a year ago, our (ancient) pressure tank developed a leak, and so I replaced it with a larger, bladder style tank. It takes a few minutes to fill, and quite a lot of water use to go below the switches 40psi for the well pump to kick in.
Yesterday, the well pump started making a louder, more high pitched hum. It can be heard clearly outside at the well head. The pump is performing the same as it was before (fully pressurizes the tank in about the same amount of time), just with this louder operating sound.
Any thoughts on what could be causing this or how to troubleshoot it before a very expensive well service call?