Hi guys,

I have a pressure pump with a Square D switch and a pressure tank connected to flooded suction from a water tank slightly uphill a moderate distance away. The delivery line is to our house.

I think the switch is meant to cut in at 20psi and cut out at 40 (factory settings for Square D, anyway).

Lately the pressure switch has had trouble turning both on and off. The tank level is getting fairly low (not empty though) - could the problem with the switch be due to a change in pressure on the suction line, or is more likely the switch itself is faulty?

Sometimes the pressure drops to practically 0psi before cutting in and gets up to 50psi and keeps running without cutting out, so I wonder if the switch might be faulty. I looked inside (disconnected power first, of course) and couldn't see anything obviously broken, though.