HELP -- While when nobody is using water, I heard that the well pump click, after 2 seconds, it would stop. This happens every 5 minutes also. Is this normal? Thanks a lot for your suggestions.

Plainly there is a leak somewhere. Could be a checkvalve/footvalve, a leaking wellpipe, or a leak somewhere between the pressure tank and the house. It makes it easier if you have a cutoff to turn off the house. If you do that, and it continues to cycle, then the leak has to be between the tank and the well.

What is interesting is the fact that it only turns on for a couple of seconds. There is probably a small air valve around the top of your pressure tank. Press that valve for a few seconds. If water comes out, then your tank's bladder is ruptured and the tank should be replaced.

If water does not come out then reset the tank pressure. It should be set to 2# below the cut in pressure. So if your pump turns on, for example, at 30#, then set the tank pressure at 28. This is done by turning off the power, draining the pressure off to zero by opening a low level faucet, and then setting the pressure.

Thanks a lot for the advise.
We cut off first the well cutoff, then the house main water cutoff and there is no well clicks now when no one use water. So the leak must be somewhere in the house pipes. We saw a little bit of water near the toilet sometimes so we will work in that area.

Ren, it could be a leaking toilet flapper valve. You can put some food coloring in the tank, then see if the water in the bowl changes color. If it does, then you know the problem.

We got a plumber in and the problem was related to an improperly installed shower tap. Two copper tubings which have different diameters were improperly welded together (a transition tubing was skipped), so the crude procedure burnt the "heart" of the multi-way valve, which cause leaking into the wall.

Glad you got it fixed. Thanks for giving us the end of the story.