The contacts on the switch are like points on an old car and can corrode and fail. The points open as they should and sometimes they remain closed even though the pump tuns off.

Well Pump Troubleshooting And Diy Repair Family Handyman
Pressure switch contacts stay closed. This may dislodge the internal spring. The contact switch in a pressure control switch ought to close turn on the pump when pressure falls below the cut in pressure setting that will be typically 20 psi or 30 psi on a new control switch. How a furnace works. The contacts stay open untill the presure once again exceeds the 115 psi cut in point. Frequent cycling of power to the switch and the presence of corrosive substances are two common causes. The contacts stay closed even when the pump is unplugged.
You make a temporary repair to contacts by filing away the affected area though be sure to kill all power to the pump before you do. Sometimes when the pressure reaches 50 lbs. Fast fix 91518 views. Usually everything works as expected. However sometimes the water stops and i find that the pressure switch contacts are closed making contact but the pump is not running. These switches are wear parts and need to be replaced at regular intervals to avoid inevitable failure.
The pressure protection valve stops airflow out of the wet tank to ctis at around 85 psi so when the contacts open it tells ctis it is out of available air. If the contacts are held open and there is no water pressure attempt to cycle the switch by pulling the contacts open. The contacts are not welded shut. Even with the points closed there may be no voltage getting through the switch. The pump then starts and everything works. To get the pump running again i use an insulated screwdriver to manually pop the contacts open.
Fast fix for non working furnace with clogged p trap or closed pressure switch reading duration. The electrical contacts in your pressure switch can degrade over time. If the switch closes turn the power back on. If the contacts remain open and there is no water pressure the switch is bad. The pressure switch contacts stay closed. Jet pump wont shut off.
The comment down the page about rust clogged plumbing is definitely relevant. The switch contacts stay closed until the pressure drops below 90 psi where the contacts open. I replaced the pressure control switchthe pressure gauge and the 4 pipe the control switch sits on.