submersible pump question....need help.

My neighbor's submersible pump isn't working right. I have the same system and I live next door. The pressure switch contacts were sticking so he bought a new switch at home depot and replaced it, making sure the wires were returned to the same screws. The pump runs and there is good water pressure inside and out, but the switch (30/50) will not cycle and the pump remains on. We put the old switch back on and it still will not cycle. It was cycling before he changed it. I check the air in the tank and the pressure was about 10 psi. the pressure hadn't been checked over the years. So, we added air to the tank to bring it up to 28 psi according to the instructions for a 30/50 switch. Still, the switch will not cycle with the new or old switch. And we noticed that the tank is not filling with water. My neighbor can't remember if the pump had been cycling rapidly lately or if water had been in the tank or not. So, the question is why won't the pump cycle on and off (stays on unless the breaker switch is turned on and off) and why isn't the tank filling with water? Thank you very much for any info you can give. Phil.

Is it possible that the inlet to the tank is plugged somehow, thereby not allowing water into the tank and not letting the pressure switch cycle? Would the pressure switch not cycle if the tank was plugged? There doesn't seem to be any water in the tank at all. It's light when gently rocked back and forth. Why would the pump cycle before the pressure switch was replaced and now it won't? Phil

A blockage in the nipple the switch is installed on could be blocked and the pressure switch may not being seeing the pressure change in real time and the switch may be lagging.

The pressure tank is not supposed to be filled with water and will be light and easy to rock.

It sounds as if there may be a water leak preventing the pump from building enough pressure to shut itself off. That may be why the contacts in the old switch were pitted etc.. Or there could be something sucked up against the pump's inlet screen.

Gary, thanks for responding. The tank is a bladder tank. Water is supposed to fill up the bladder, right? Even with 10 psi when initially checked there was no water making it into the tank. None at all. It was completely empty. No water at all. And, there was plenty of water coming into the house and out the garden hose. My neighbor told me that over the last year or so the showers would have almost no pressure. Now, when running just from the pump he has plenty of pressure. Tank problem?

If the pressure does not build enough to trigger the switch you have a leak in the drop pipe in the well or between the well and the house. The pump has to overcome the tank pressure and cannot due to the leak.

There is PLENTY of pressure from the pump. according to my neighbor the shower pressure hasn't been this good in 3 months. Plenty of water pressure at the the outside garden hose valve too. But, no water getting into the tank. My theory is this: there is a blockage at the tank. The pump runs continuously because the pressure from the pump exceeds the 50 psi that the pressure switch would require to shut the pump off. And, no water enters the tank = blockage. maybe over time the bladder fell due to low pressure in the tank (was about 10 psi or less when initially checked) and it fused together (rot, etc...maybe a leak caused it). and now water will not fill the bladder. I checked the tank pressure just an hour ago and it showed 27.5 psi. If everything worked perfectly the water pressure would fill the bladder in the tank and the pressure switch would shut if off at 50 psi. But because the bladder is collapsed and fused\blocking the inlet somehow (maybe) the switch will not shut off the pump because the well pump is greater than 50 psi all the time and that's why it runs continuously and won't shut off. What do you guys think? (I think my neighbor needs a new tank). Phil.

You might be right about the tank but the switch should be in the line BEFORE the tank.

As long as there is no water running in the house the pump should develop enough pressure in the line to cause the switch to turn the pump OFF.

So, another question would be: does the pressure switch measure general line pressure or pressure coming back from the tank? Also, why would there be great pressure in the house with the pump running yet it won't cause the pressure switch to shut off? Can anyone think of any reason at all why water would not be going into the tank if there is good pump pressure? Any reason at all other than a blockage of some kind? What is the average pressure of say a 1 HP submersible pump? Thanks.

The pressure switch can only measure the pressure in the line where it is installed. The pump is what produces the water pressure- the bladder tank is only there to provide a "cushion" and provide a set amount of drawdown to prevent the pump from excessively cycling on and off.

A bladder tank is installed with a "T", allowing only one path for water to flow both in and out. I suppose it's possible for the bladder to twist or otherwise stop flow into the tank. There can be no water in the bladder to properly measure the air charge. If the air pressure is higher than the water pressure, the tank will not fill.

In a common installation, there is a pressure gauge installed in the tank tee right next to the pressure switch. This is where one should observe the line pressure and verify proper operation of the switch. If the pump cannot produce 50 psi due to a leak or pump wear, it will not reach the cutout setting of the switch.

A well pump has a motor that is rated in HP and a pump that is rated in GPM. It is very possible for a pump to pressurize the water piping in excess of 100 psi, but the depth of the well and condition of the pump and motor might prevent it.

Thank you. That was a good explaination. My neighbor currently has no pressure gauge installed near the switch. So I'll ask him to buy one and install it so we can see what the line pressure is. That will give us more diagnostic information to work with. I guess it's possible that the pump is actually putting out less than 50 psi and the switch isn't sensing it and keeps the pump running. Does this mean the pump needs to be replaced? What if a 20/40 switch were installed instead? That may help in the short term but it looks like the pump may still need to be replaced either way. Phil.

No problem, learned a lot here myself.

If the pump made the pressure before and cannot anymore, it could be that there is a leak as stated before. The leak could be below the waterline down in the well. It could also be that the pump is worn.

Pressure switch is adjustable and can be turned up or down. The paperwork that came with the switch will explain better than me typing.