Just my experience or inexperience ....Just got done getting water back in my house . I came home yesterday to find i have no pressure . Pump runs but no pressure would build up , had lots of water in the well . So i replaced the foot valve , with no positive results , well then i thought it must be the jet pump, so i buy new jet pump and install it. Still no pressure would build up, so i call a pro and he said it could be the venturi. Next i replace the venturi , what else could it possibly be was running through my head .The pro came and he does not deal in jet pumps just submersible pumps .Ok put one in i said , so he does and connects it to the 1" line comming in . Starts the pump up ,he get no pressure in the house either . I go to the well and find the ground saturated with the water that should be going in to the house , now i find out that the pitless adapter that is buried 4' under frozen ground has a rusted fitting that is the cause of all my troubles . We switched over to the 1.25" line and everything is good .