You never did say if it was a jet pump or a submersible, i'm asuming it
is a jet pump since it is at your cottage. You will only find a 6"x3/8 brass nipple on a submersible set up, on a jet pump set up you will
find a 1/8 tube that runs from the pressure swich to the head of the pump checkit to see if it is plugged or the fitting going into the head of the pump. Another thing to do is when it happens next time carefully take the grey cover off the pressure switch when the power is on and see if the points are open or closed. If the points are closed and your pump is not running there could be a problem with that switch. Trouble shooting
a pump is hard to do with out a multi meter.