I have a cabin with a jet pump located in the basement. It's a shallow well, so that's all that is needed. I came there one day and found the pump was running continuously. Could have been running for several days because no one had been there. There was also poor water pressure. I checked the electrical contacts on the pressure switch and all of that was working. All of a sudden I got the idea that the pressure switch was jammed. I hit it with a piece of wood and the pump stopped and there was pressure again. Apparently there was a chunk of rust stuck in it. It's been fine ever since. In fact I planned to take it off and clean it out, but since everything is working, I didn't do anymore.
A neighbor told me that the reason that happened is because I have the check valve mounted almost horizonally. It's located in the pipe where it enters the basement wall from the well, and right before the pump. It is almost horizontal, just slightly off horizontal because the pipe slopes down a little toward the entry point in the wall, and the pump is a little higher.
While what he said does make a little sense, (saying nothing can get stuck on there then), I dont really know if it matters all that much, because it's been that way for over 20 years and never jammed up before. However, in the past I kept the house heated in winter, and this year because of the price of fuel. I drained all the water and this happened shortly after turning it on again. So, I could see where chunks of rust broke loose.
Anyhow, is there any "rule" about the position of them? He's not a plumber, so it might just be rumor, but I thought I'd ask.
Thanks
Gerry