Hello - My mother has a well pump and has been complaining that the water pressure has gradually been getting lower so I decided to look at it. First thing that I noticed is that the pressure gauge is stuck on 20 PSI....it has yet to move after days. I released all the water from the tank and replaced the switch. No change. The switch is stuck with the contacts touching but the gauge does not move. What could this be? By banging on the tank, the bottom has a thug while the top is a hollow sound (That eliminates the tank right?) Is the well pump bad? How do I confirm this? Thanks for your help

Im trying to put down a flotec 11/2 hp 239 v my question isif can I put. A 1" pipe instead of 11/4 what will be diferent,