Why does my pump on my water well keep coming on?

Perhaps it is priming itself on an automatic switch.

you have a leak somewhere -- garden hose, in piping between pump and house -- need to find it!!

you have a leak somewhere! Maybe a garden hose is running - or there's a leak between the pump and the various faucets/toilets, etc in the house

you might want to ck your pressure tank, we just replaced ours and it was doing the same thing. The tank has a bladder in it to create pressure, it can rupture and then the pump kicks on and off for no reason. Call a plumper to ck it for you

Do you have access and a crawl space under the house, if so check for leaks or pools of water. If you have a shut off valve to the plumbing in the house, shut it off and see if the pump keeps cycling,( turning on and off), if it does you have isolated the house from being the problem and it's probably an underground water main supply line issue, also if there is a shut off valve AFTER the pressure tank, that can be shut off to help isolate the leak issue. There are different variations in pressure switches, but lets say you have a 30 - 50 pressure switch. When the pressure in the pressure tank drops to 30 lbs of pressure, the switch activates the pump and the pump runs until the pressure in the tank reaches 50 lbs and shuts of until the pressure drops to 30 lbs once again and goes through the same cycling stages ---30 on 50 off. If you have a bladder tank it is less likely to become water-logged, however if you have the older type system and the pressure tank is simply a large, (40 or 50 gallon tank without a bladder) it could be water-logged, meaning the tank has become so full of water there is very little air space left in the tank which will cause rapid cycling. ( air will compress, but water won't as easily. with minimal air space in the tank the pressures will change rapidly causing the pressure switch to activate the pump much more frequently!!) A tank that doesn't have a bladder/diaphragm should only be about 1/2 full of water in typical operation allowing the other 1/2 of the tank with air to compress during the on off cycles and creating a much more even flo of water without extreme pressure differences. If there are't any water leaks, there could be an air leak, and as one of the previous comments mentioned, the diaphragm of a bladder tank could have failed or ruptured.The newer types of pressure tanks with a diaphragm have been built to keep a separate air compartment from the water compartment by using a rubber membrane attached to the inner wall of the tank allowing it to stretch during the water pump stage towards the air compartment creating higher air pressure until the proper pressure is reached and then the compressed air pushes back on the diaphragm towards the water until the pressure drops low enough to cause the pressure switch to kick the pump back on! You really need to get the problem resolved because your pump is being over used and you could end up having to replace your pump as well--Costly!! I hope that helps-- knowing the basics of how a well and pump system works can save you a lot of money if you can determine whether to call a plumber, a well service co., or locate the issues and be a DIYER!

If you have a submersible pump the leak could also be in the pipes in the well, or sand/debris in the foot valve.

Lots of different possibilities. I think most all have been covered. But if you don't find signs of a leak, your pressure tank has a switch which could be bad, Leak in pressure tank you should see water in or around the pump house if if is above ground. Pressure switch is a common item to need to replace. I think Yoder explained in depth most of the points. If this is the main source of water to your home you need to get it taken care of ASAP, or you will have an even bigger problem.

I'm going with Chris Gaines comment for the most obvious first choice. We had the same thing going on with our well pump and it turned out that we had a leak in the pipe in the well itself, so water was just coming partway up to the pressure tank, then leaking out back into the well. So you couldn't see or hear anything other than the pump being constantly phasing on/off.

Sounds like you've got a pesky issue with your water well pump.

It could be due to a few things, but one common culprit is a faulty pressure switch. That little guy's in charge of telling your pump when to kick on and off based on the water pressure in your system. If it's acting up, it could be causing your pump to go haywire. Another possibility is a leaky faucet or toilet that's using up water without you knowing it. So, double-check all your fixtures, man! And if you've got a water swivel for drilling, make sure it's properly installed and not causing any problems. If all else fails, you may need to call in a pro to take a look.