Pressure tank

[tun37ja]

My water pressure tank seems to be going on and off too often; when the pressure goes down to 35 PSI it turns on and at 50 PSI it shuts off. this cycle is repeated about two and a half minutes; ( this goes on while no water is being run in the house ) while the motor is running there is a sound of falling water inside the tank. I closed the outlet valve to make sure there is no leak in the plumbing, but it keeps cycling just the same. I'll appreciate any in put, do I have a problem or is this normal ?
Thanks

[HayZee518]

Inside the tank is an air filled rubber bladder. This provides a cushion when the pump turns on and also enhances the in line water presssure. If this bladder is punctured or broke then the pump will rapidly cycle on - off trying to keep up the line pressure. If the bladder is ok but there's no air in there, the same cycling will happen. Try using a bicycle pump and pump iy up a little, If you hear gurgling when you are pumping the bladder's shot.

[Hube]

Remove the pressure tanks air valve CAP,depress valve pin for a second or two.. If no water is apparent (water here indicates a leaky bladder) If no leak proceed as follows.:

Shut off pump power, drain tank of all water, with a bike pump put air into tank so its 2 lbs psi below the 'cut-in' setting (in your case 35 minus 2 = 33 lbs psi
Turn power to pump back on and try it out..
good luck.
PS; Normally a system has a 20 psi differential.,eg;20-40 30-50, 35-55. this 20 spread will allow you to use more water before activating the pump. This adjustment is usually indicated on the inside of the pressure switch cover plate. If not, post back and we can describe how to manage this adjustment.

[LazyPup]

I don't believe the problem is in the pressure tank. Even if the bladder was ruptured the air would still be in the tank and the pressure would remain constant.

In order for the pressure to drop signalling the pump to run again the water level in the tank must be dropping.

In the post they state that they turned off the supply line at the output of the tank and the problem still occured. Given that the water level in the tank must drop in order to lower the pressure, and given that the water cannot be leaking in the house distribution system when the main water shutoff valve is off, I would suspect a defective check valve on the pump which is allowing some of the water to backflow to the well.