I live in a older home in a small rural town with a shallow well in the basement. I recently replaced the pump (it was leaking). The old pump was also cycling on and off sometimes very fast (chattering) both at cut off and cut on pressure. When I replaced the pump it seemed to fix it for a while but then it came back. I replaced the cheap pressure switch that came with the pump with a new 20-40 psi Square D switch. It worked for a while but then it started up once again at both cut-off and cut-on pressures. I used to have a very small (19 gal) pressure tank and I could get the chattering to stop by adjusting the air pressure in the pressure tank. Finally the water line to the pressure tank broke so I replaced the tank with a new 44gal bladder tank. I followed the instructions and reduced the air pressure in the tank to 2psi below my pump cut in, and drained all the air out of the system. This did not help the chattering problem. I was told that my foot valve at the bottom of my well could be clogged that may be causing my pump to do this. Also I read some of your post about pumps cycling could be caused by a faulty check valve. Any ideas?

"I was told that my foot valve at the bottom of my well could be clogged that may be causing my pump to do this. Also I read some of your post about pumps cycling could be caused by a faulty check valve."

The foot valve is a check valve located at the bottom of the well while a check valve's located on the suction line above ground. They both do the same fuction. Regards, Tom

But the answer is yes a bad check [or foot ] valve could cause this. The pump builds up pressure, cuts off , the water runs back down the well.

Please explain the cut-in and cut-off pressures of a water pump.

Cut in means the pump starts, cut out the pump stops.