4" well, 1.5hp submersible pump...I noticed today that my pump was cycling every twenty minutes when no water was being used. I shut off the valves downstream from the tank to make sure it wasn't something in my house. My setup has a check valve between the pump and tank. The check valve has both the pressure switch and a Schrader valve Tee'd off of it. With the pump not running, I pressed the Schrader valve stem and water squirted out (a lot!). I could also see the pressure dropping at the tank very slowly.

I drained the bladder-less tank, "tapped" on the check valve a few times, then refilled the tank. When the pump shut off, the Schrader valve was drawing air for a minute or so. After that, when I pressed on the valve stem, no water came out like before.

So...I'm thinking I've got a sticking check valve, and tapping it a few times when the tank was empty freed it up temporarily. Am I missing anything else here, or do I just need to replace the check valve? Should I be concerned that when the check valve is stuck open, I'm slowly losing pressure back thru the well?