I've got a WellMate tank (WM20-WB) with a Square D 9013 FSG2 valve. About a week ago, my pressure increased noticably and I'm not sure why. Any thoughts about why this could happen?
Either the nipple going to the Square D 9013 is clogged, or the switch itself is bad. You should also have a pressure relief valve that pops off if the pressure gets too high.