The question I have ,I noticed a few weeks ago, my pump seemed to run longer than normal. I noted the gauge at the switch read 50 psi. A few days later the pump did not shut off after 30 min. Psi was only at 46. So I shut power off at pump. No water was used for 4 hours. I re-checked gauge still at 46. So I adjusted switch to cut out at 45. Things were good for a day or two. The same issue, pump running for over half hour, looked at gauge read 42 psi. This has been going on for several weeks. Now I'm down to only being able to build 34 psi. I have gone 24 hours without using any water in the house, gauge still reads same. So I am assuming there are no leaks above the check valve. And the well has had plenty of time to recover, bad pump? Bad tank? Need help! Don't want to spend a lot money on service calls.

Sounds like switch and gauge may be partially blocked by debris. Remove and clean.
If you change switch setting you should also adjust precharge air pressure.

Sounds like switch and gauge may be partially blocked by debris. Remove and clean.
If you change switch setting you should also adjust precharge air pressure.
I installed new switch today and gauge with pipe and T feeding it. Re-charged pressure tank, same problem. Got a well guy coming Friday. I would pull the pump myself if it was going to be above 32 degrees, but I won't see that until March. I live in central WI. Thanks for the help.

The tank is not likely to be the problem. Sounds like a pump going bad or possibly a leak in the wellpipe.