What I learned about well pumps
In the last 10 days I got a crash course on well pumps. In our last house we had a deep well with a submersible pump. It was in the well, I never saw it, it always worked. The most I learned about that well was how the holding tank worked. The rubber bladder in our tank failed and we always had water, but the pump would "short cycle"... so I replaced the holding tank (but that's another story).
In this house we have a shallow well jet pump. This is a pump in the basement and it is set up for wells less than 25' deep, there are other jet pumps for deeper wells but they are plumbed differently. Our pump has one suction inlet and one outlet (that makes it a shallow well jet pump).
Last week we noticed that the pump pressure was dropping so low (30 psi) that the pump would just never shut off. Fortunately after hearing it run for an hour or so Tammy asked me to look at it. I had no clues... So Tammy called the nice well pump people who left their sticker on our pump and told them our life story. They were actually kind enough to walk me through how to clean out a pump by opening the cleanout plug. Amazing how much iron scale accumulates in there!
So last week we were able to get the pump making 50psi again by cleaning out the inlet... but it would still not turn off -- so we spent a week manually turning the pump on when we needed water, then turning it off to stop it from running. Today I googled the pressure switch and figured out how to adjust it. By backing off the cut in/out pressure spring by 1 1/2 turns I was able to get the pump to operate normally again. It's making 50 psi at the max and coming back on again at 30 psi.
At this point I'm not sure if the pump is just so crudded up that it is incapable of producing much more than 50 psi or (my suspicion) that the iron crud got into the pressure switch and messed up it's calibration. Hopefully this will do it. We have found we really like (automatic) running water. If this doesn't do the trick my next try will be to clean out the tube leading from the pump to the pressure switch, then replace the switch and finally if all else fails replace the entire pump. Hopefully it won't come to that. I hate plumbing.