Originally Posted by
jlisenbe
Slight correction. The little tube does not run from the pump to the box, it runs from the water pipe to the box. I know Tom knows that... just a miskey.
That would definitely be worthwhile to check. The big question is this: When you don't have much pressure in the house, check the pressure gauge to see how much pressure you have. If the pump is running at that point, when pressure is very low, then that control box is doing its job. You can tell if the pump is on by simply feeling the pipe where it comes out of the well. There is generally a slight vibration when the pump is running.
Just so you'll know, the control box, known as the switch, is a pressure sensitive device. As water is used, the pressure tank empties and pressure falls. When it reaches a set point, say 30# for example, the switch turns the pump on. The pump pumps until pressure goes up to another set point, for example 50#, and then the switch turns off the pump. Pressure goes back down until the switch turns the pump back on, and the cycle just continues. If the little pipe Speedball referred to is clogged, then the switch cannot sense pressure and doesn't cut the pump on.