The pressure switch to a well pump may shut down a well or cause the water not to flow, especially if both the switch and a pressure tank are affixed to the system. Both parts can cause an over-circulation of water, which, in turn, shuts down a system. The shut-off measure is a safeguard in case a pipe breaks while water is being pumped from the well.
The pressure switch for a well-pumping system typically is found in a gray box that sits on the feed line between the pump and the pressure tank. A silver bar sits next to the box. When the bar is tripped, it rests parallel to the ground. If the trip handle is operational, it sits at approximately a 45-degree angle.
To reset the pressure switch, shut off the water valves, and lift the handle until it is engaged. Allow the tank to fill with water before reopening the valves.
If everything is working correctly, the pressure in the tank should read 2 pounds per square inch less than the setting for the pressure switch. If the setting for the pressure switch is 28 psi, then the tank's reading should be 26 psi.
A power surge can cause a breaker to trip and shut off the flow of water as well. In order to fix the problem, find the pump's circuit breaker, and switch it off and on again.