With a faucet open, my pump pressure drops from 50 psi down to 30 psi, pump turns on, but no pressure builds back up. The gauge stays at 30 psi for a few minutes, then drops down to ~0 psi and the pump is making a racket. I lose water at the faucet at which point I shut down the faucet valve. Pressure now builds back up to 50 psi and the pump shuts off as it should. The top half of the holding tank appears to be empty and the bottom half is full as it should be. The weather has been very hot and dry (East coast). Do you suspect the water table or a mechanical problem?

Thank you

How deep is the well? Drilled or bored well? Is this a deep well ,shallow well, submersible or with a jet foot valve. If it is a shallow well, 25" or so, you are probably running out of water. How much water can you run out before the noise starts. If it is 10-15 gallons, you are out of water. Can you lower the foot valve?

Thanks for the comeback. The well is a deep well with the pump above ground (basement). I suspect I have a foot valve, but cannot be sure. If I do, I would not know how to lower the valve. Once I close the faucet, the pressure builds back up to 5

BT, how many pipes go from your pump down the well? If it's just one, then you can't pump from much more than 25'. If it's two, then you can get down deeper than that, and you would definitely have a foot valve. Since the pump can build pressure back to 50# once you turn the faucet off, then it would seem you have a volume problem. The pump can still build pressure, but can't supply much water.

Try this: Run a short garden hose into a 5 gallon bucket. With the pressure at 50 and the pump not running, run water into the bucket. See how many gallons you can get before the pressure drops to 30 and the pump cuts on. At that point, turn off the faucet and time how long it takes your pump to get back to 50 and cut-off. Do a little math, and you'll know how many gallons per minute your pump is supplying. Ideally, it would be at least 5 or 6 gallons per minute. I'm going to guess that you are nowhere near that.