I have a problem with the pressure switch on my well. Thought I had a pipe partially frozen since temp was in mid teens a couple of nights. Thawed pipes and reinsulated all. Problem is the pressure switch is clicking in and out constantly. I have water for about 30 seconds in master bath(closest to tank and switch). Pressure drops to zero and switch constantly kicks in and out. Tank and switch are under home and have never had problems in 7 years with freezing. Tank, switch and pump are new in last 6/8 months. With weather being so cold, could I have lost pressure in tank? Water in home pulses as switch is kicking in and out before I lose all water. Will build back up in minutes, but does same thing. I have water and pump sits in about 40 feet of water so I know the well is good. Water is clear not stained.
Any help appreciated. Thanks

The first thing I would look at is the check/foot valve. If it's bad the pump will pump to pressure, shut off and immediately start up again. Let me know, Tom

If you have a regular pressure tank, not a bladder tank, this sounds like a water logged tank. The tank is completely filled with water. There is no air in the tank to be compressed. You cannot compress water. As water passes through the tank it absorbs some of the air. Eventually all of the air is gone and the tank is full of water. A small amount of water from the pump will cause great increase in the pressure. A small amount of water released at the faucet will cause great drops in pressure. Turn off pump. Open tank drain valve or plug. Open at least one faucet. Allow all the water to drain out. Close drain. Restart pump. When tank is 1/3 full of water, pressure will be 40 lbs. When tank is 2/3 full of water pressure will be 60 lbs. of pressure. Pump should shut off in this range and come back on at about 40lbs.

Considering the tank is new, I doubt that it is other than a bladder tank, though I guess it's possible. The pulsing you describe does sound like a waterlogged tank. However, Speedball is entirely correct in saying that the checkvalve could be the problem. IF it is the checkvalve, the pump will cycle even when water is not being used in the house. This is because the checkvalve is allowing water to simply run back into the well as soon as the pump turns off. So the pump builds up pressure only to see the water bleed right back into the well, causing the pump to have to cycle again.

A waterlogged tank will cause the pump to shortcycle only when water is being used. You might want to simply check the tank to be sure it still has air in it. It is simple enough to do by simply pressing the air valve on top of the tank for a couple of seconds. If water comes out, then that's trouble. You can also tap the tank with a screwdriver handle, beginning at the bottom. You can hear the change in pitch when you move into air. The tank should be roughly half air, half water.

You say the pump is kicking in and out. Does it get to cut out pressure and cut off,even if only for a few seconds, or does it seem to cut off at random points?