Pressure Switch Chatter

[oink]

Have you checked the pressure with the tank empty yet? There should be no water in the tank at that point. Then fill with air as outlined by Obie. If the pressure is way off or the tank is waterlogged it will act as you've described. As mentioned by Obie, a busted bladder will cause it. If the bladder is blown you can limp along for awhile by adding extra air but it won't act like a bladder tank any more. It will reflect it's true size and air will have to be added more often. The larger the tank the better it will work with a busted bladder. Do you have a gauge on your system so you can observe the pressure while it running and cycling?

Good luck.