I just closed on a new (old) house and have some well issues. I have a 1/2hp Wayne shallow well jet pump on a 20 gallon plain tank. No bladder. No pressure gauge, but a 30/50 switch on the pump.

Pump cycles on after about 1/2 gallon water draw. Runs for about 12 seconds and shuts off. (My math tells me the pump is producing about 2.5 gpm.) The well is a driven point 24 feet down. I'm not certain where the SWL is. I'm guessing about 15 feet.

So far I've replaced the AVC, and I've drained the tank a couple times to try to make sure it isn't waterlogged. Pump still cycles on after about 1/2 gallon draw.

So it seems I have two problems. The first is that the pump shouldn't be cycling so often. The second is that I should be getting a higher flow (unless SWL is near the bottom of the well). Trying to solve the cycling problem first. Since I replaced the AVC and saw no change, all I can think is that there is a leak in the supply pipe somewhere and I am drawing air in the line, and hence the tank, every time the pump turns on, which is why I have essentially no usable volume in the tank. Any other ideas? Bad pressure switch? Cavitating pump? I'm considering replacing the plain tank with a 20 gallon bladder tank, but if I have an air leak in the supply pipe will I still end up with the same problem? What happens in a driven point well if the pump is trying to draw water faster than water can come through the screen? Does that add air to the system too?

Any suggestions appreciated.

 

That's where I'd start.

I'm not all that big on the AVC (auto vent control) float systems.